module RSpec::Matchers

def be_a_kind_of(expected)

expect(5).not_to be_a_kind_of(Float)
expect(5).to be_a_kind_of(Numeric)
expect(5).to be_a_kind_of(Fixnum)

@example

Passes if actual.kind_of?(expected) 
def be_a_kind_of(expected)
  BuiltIn::BeAKindOf.new(expected)
end