error

/usr/local/lib/ruby/gems/1.9.1/gems/sequel-2.10.0/lib/sequel_model/record.rb:52:in `[]=': undefined method `include?' for nil:NilClass (NoMethodError)
	from /usr/local/lib/ruby/gems/1.9.1/gems/sequel-2.10.0/lib/sequel_model/base.rb:445:in `block (3 levels) in def_column_accessor'
	from /home/max/Projects/writetogether/model/init.rb:16:in `<top (required)>'
	from start.rb:14:in `require'
	from start.rb:14:in `<main>'

init.rb

# Here goes your database connection and options:
require 'sequel'

begin
  DB = Sequel.sqlite
rescue NoMethodError
  raise LoadError, 'Install latest Sequel gem'
end

require 'model/user'

unless User.table_exists?
  puts "table doesn't exist"
  User.create_table
  u = User.new
  u.username = 'admin'
  u.password = 'password'
  u.save
#  User.create(:username => 'admin', :password => 'password')
  #User << {:username => 'admin', :password => 'password'}
  # none of the above three methods work
  puts "user created"
end

user

class User < Sequel::Model
  set_schema do
    primary_key :id
    varchar :username
    varchar :password
  end
end