module RSpec::Matchers

expect("spread").not_to include("red")
expect("spread").to include("read")
expect([1,2,3]).not_to include(4)
expect([1,2,3]).to include(2,3,4) # fails
expect([1,2,3]).to include(2,3)
expect([1,2,3]).to include(3)

@example

and it will only pass if all args are found in collection.
collections and Strings. You can also pass in multiple args
Passes if actual includes expected. This works for

def include(*expected)
  BuiltIn::Include.new(*expected)
end