pausable.sol

    // this code is basic token with pausable
    pragma solidity ^0.5.0;
    
    /**
     * @title ERC20Basic
     * @dev Simpler version of ERC20 interface
     * @dev see https://github.com/ethereum/EIPs/issues/179
     */
    contract ERC20Basic {
      function totalSupply() public view returns (uint256);
      function balanceOf(address who) public view returns (uint256);
      function transfer(address to, uint256 value) public returns (bool);
      event Transfer(address indexed from, address indexed to, uint256 value);
    }
    
    /**
     * @title ERC20 interface
     * @dev see https://github.com/ethereum/EIPs/issues/20
     */
    contract ERC20 is ERC20Basic {
      function allowance(address owner, address spender) public view returns (uint256);
      function transferFrom(address from, address to, uint256 value) public returns (bool);
      function approve(address spender, uint256 value) public returns (bool);
      event Approval(address indexed owner, address indexed spender, uint256 value);
    }
    
    /**
     * @title SafeMath
     * @dev Math operations with safety checks that throw on error
     * @notice https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/math/SafeMath.sol
     */
    library SafeMath {
    	/**
    	 * SafeMath mul function
    	 * @dev function for safe multiply, throws on overflow.
    	 **/
    	function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    		uint256 c = a * b;
    		assert(a == 0 || c / a == b);
    		return c;
    	}
    
    	/**
    	 * SafeMath div funciotn
    	 * @dev function for safe devide, throws on overflow.
    	 **/
    	function div(uint256 a, uint256 b) internal pure returns (uint256) {
    		uint256 c = a / b;
    		return c;
    	}
    
    	/**
    	 * SafeMath sub function
    	 * @dev function for safe subtraction, throws on overflow.
    	 **/
    	function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    		assert(b <= a);
    		return a - b;
    	}
    	
    	/**
    	 * SafeMath add function
    	 * @dev Adds two numbers, throws on overflow.
    	 */
    	function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    		c = a + b;
    		assert(c >= a);
    		return c;
    	}
    }
    
    /**
     * @title Basic token
     * @dev Basic version of StandardToken, with no allowances.
     */
    contract BasicToken is ERC20Basic {
      using SafeMath for uint256;
    
      mapping(address => uint256) balances;
    
      uint256 totalSupply_;
    
      /**
      * @dev total number of tokens in existence
      */
      function totalSupply() public view returns (uint256) {
        return totalSupply_;
      }
    
      /**
      * @dev transfer token for a specified address
      * @param _to The address to transfer to.
      * @param _value The amount to be transferred.
      */
      function transfer(address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[msg.sender]);
    
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        emit Transfer(msg.sender, _to, _value);
        return true;
      }
    
      /**
      * @dev Gets the balance of the specified address.
      * @param _owner The address to query the the balance of.
      * @return An uint256 representing the amount owned by the passed address.
      */
      function balanceOf(address _owner) public view returns (uint256) {
        return balances[_owner];
      }
    
    }
    
    /**
     * @title Standard ERC20 token
     *
     * @dev Implementation of the basic standard token.
     * @dev https://github.com/ethereum/EIPs/issues/20
     * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
     */
    contract StandardToken is ERC20, BasicToken {
    
      mapping (address => mapping (address => uint256)) internal allowed;
    
      /**
       * @dev Transfer tokens from one address to another
       * @param _from address The address which you want to send tokens from
       * @param _to address The address which you want to transfer to
       * @param _value uint256 the amount of tokens to be transferred
       */
      function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
        require(_to != address(0));
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
    
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        emit Transfer(_from, _to, _value);
        return true;
      }
    
      /**
       * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
       *
       * Beware that changing an allowance with this method brings the risk that someone may use both the old
       * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
       * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
       * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
       * @param _spender The address which will spend the funds.
       * @param _value The amount of tokens to be spent.
       */
      function approve(address _spender, uint256 _value) public returns (bool) {
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
      }
    
      /**
       * @dev Function to check the amount of tokens that an owner allowed to a spender.
       * @param _owner address The address which owns the funds.
       * @param _spender address The address which will spend the funds.
       * @return A uint256 specifying the amount of tokens still available for the spender.
       */
      function allowance(address _owner, address _spender) public view returns (uint256) {
        return allowed[_owner][_spender];
      }
    
      /**
       * @dev Increase the amount of tokens that an owner allowed to a spender.
       *
       * approve should be called when allowed[_spender] == 0. To increment
       * allowed value is better to use this function to avoid 2 calls (and wait until
       * the first transaction is mined)
       * From MonolithDAO Token.sol
       * @param _spender The address which will spend the funds.
       * @param _addedValue The amount of tokens to increase the allowance by.
       */
      function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
        allowed[msg.sender][_spender] = (
          allowed[msg.sender][_spender].add(_addedValue));
        emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
      }
    
      /**
       * @dev Decrease the amount of tokens that an owner allowed to a spender.
       *
       * approve should be called when allowed[_spender] == 0. To decrement
       * allowed value is better to use this function to avoid 2 calls (and wait until
       * the first transaction is mined)
       * From MonolithDAO Token.sol
       * @param _spender The address which will spend the funds.
       * @param _subtractedValue The amount of tokens to decrease the allowance by.
       */
      function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
        uint oldValue = allowed[msg.sender][_spender];
        
        if (_subtractedValue > oldValue) {
          allowed[msg.sender][_spender] = 0;
        } else {
          allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
        }
        
        emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
        return true;
      }
    
    }
    
    /**
     * @title Ownable
     * @dev The Ownable contract has an owner address, and provides basic authorization control
     * functions, this simplifies the implementation of "user permissions".
     */
    contract Ownable {
      address public owner;
    
    
      event OwnershipRenounced(address indexed previousOwner);
      event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    
    
      /**
       * @dev The Ownable constructor sets the original `owner` of the contract to the sender
       * account.
       */
      constructor() public {
        owner = msg.sender;
      }
    
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
        require(msg.sender == owner);
        _;
      }
    
      /**
       * @dev Allows the current owner to transfer control of the contract to a newOwner.
       * @param newOwner The address to transfer ownership to.
       */
      function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0));
        emit OwnershipTransferred(owner, newOwner);
        owner = newOwner;
      }
    
      /**
       * @dev Allows the current owner to relinquish control of the contract.
       */
      function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(owner);
        owner = address(0);
      }
    }
    
    /**
     * @title Pausable
     * @dev Base contract which allows children to implement an emergency stop mechanism.
     */
    contract Pausable is Ownable {
      event Pause();
      event Unpause();
      event NotPausable();
    
      bool public paused = false;
      bool public canPause = true;
    
      /**
       * @dev Modifier to make a function callable only when the contract is not paused.
       */
      modifier whenNotPaused() {
        require(!paused || msg.sender == owner);
        _;
      }
    
      /**
       * @dev Modifier to make a function callable only when the contract is paused.
       */
      modifier whenPaused() {
        require(paused);
        _;
      }
    
      /**
         * @dev called by the owner to pause, triggers stopped state
         **/
        function pause() onlyOwner whenNotPaused public {
            require(canPause == true);
            paused = true;
            emit Pause();
        }
    
      /**
       * @dev called by the owner to unpause, returns to normal state
       */
      function unpause() onlyOwner whenPaused public {
        require(paused == true);
        paused = false;
        emit Unpause();
      }
      
      /**
         * @dev Prevent the token from ever being paused again
         **/
        function notPausable() onlyOwner public{
            paused = false;
            canPause = false;
            emit NotPausable();
        }
    }
    
    /**
     * @title Pausable token
     * @dev StandardToken modified with pausable transfers.
     **/
    contract PausableToken is StandardToken, Pausable {
        string public constant NAME = "";
        string public constant SYMBOL = "";
        uint256 public constant DECIMALS = 18;
        uint256 public constant INITIAL_SUPPLY =  * 10**18;
    
        /**
         * @dev Transfer tokens when not paused
         **/
        function transfer(address _to, uint256 _value) public whenNotPaused returns (bool) {
            return super.transfer(_to, _value);
        }
        
        /**
         * @dev transferFrom function to tansfer tokens when token is not paused
         **/
        function transferFrom(address _from, address _to, uint256 _value) public whenNotPaused returns (bool) {
            return super.transferFrom(_from, _to, _value);
        }
        
        /**
         * @dev approve spender when not paused
         **/
        function approve(address _spender, uint256 _value) public whenNotPaused returns (bool) {
            return super.approve(_spender, _value);
        }
        
        /**
         * @dev increaseApproval of spender when not paused
         **/
        function increaseApproval(address _spender, uint _addedValue) public whenNotPaused returns (bool success) {
            return super.increaseApproval(_spender, _addedValue);
        }
        
        /**
         * @dev decreaseApproval of spender when not paused
         **/
        function decreaseApproval(address _spender, uint _subtractedValue) public whenNotPaused returns (bool success) {
            return super.decreaseApproval(_spender, _subtractedValue);
        }
        
        /**
       * Pausable Token Constructor
       * @dev Create and issue tokens to msg.sender.
       */
      constructor() public {
        totalSupply_ = INITIAL_SUPPLY;
        balances[msg.sender] = INITIAL_SUPPLY;
      } 
    }