class RSpec::Matchers::DSL::Matcher

def expected
  if @expected.size == 1
    RSpec.warn_deprecation(
      "Custom matchers in 3.x will set expected to be a single value "+
      "(when provided as such) rather than an array. This may change "+
      "the behaviour of your matcher.\n"+
      "To continue to access this as an array use `expected_as_array`\n"+
      "Called from: #{ RSpec::CallerFilter.first_non_rspec_line }\n\n"
    )
  end
  @expected
end