lib/rspec/block_is_expected/matchers/not.rb
RSpec::Matchers.define_negated_matcher(:not_change, :change)
RSpec::Matchers.define_negated_matcher(:not_include, :include)
RSpec::Matchers.define_negated_matcher(:not_eq, :eq)
RSpec::Matchers.define_negated_matcher(:not_raise_error, :raise_error)