class RSpec::Matchers::DSL::Matcher

def respond_to?(method, include_private=false)

from the `@matcher_execution_context` as well.
Indicates that this matcher responds to messages
:nocov:
for 1.8.7 
def respond_to?(method, include_private=false)
  super || @matcher_execution_context.respond_to?(method, include_private)
end