ruby check var for any case: 1) is an integer; 2) is an integer in string; or 3) is an integer in string in symbol

gistfile1.txt

Last login: Fri Feb 23 16:16:47 on ttys004
dev-2:pumpone-rails dev$ irb
irb(main):001:0> def is_int?(arg)
irb(main):002:1>   arg.to_s.to_i.to_s == arg.to_s
irb(main):003:1> end
=> :is_int?
irb(main):004:0> is_int? 1
=> true
irb(main):005:0> is_int? "1"
=> true
irb(main):006:0> is_int? "one"
=> false
irb(main):007:0> is_int? :one
=> false
irb(main):008:0> is_int? nil
=> false
irb(main):009:0> is_int? :"1"
=> true