new_contents: from nose.tools import istest, assert_equal
  
  from mammoth import document_matchers
  
  
  @istest
  def equal_to_matcher_is_case_insensitive():
      matcher = document_matchers.equal_to("Heading 1")
      assert_equal(True, matcher.matches("heaDING 1"))
      assert_equal(False, matcher.matches("heaDING 2"))
  
subject: Add test for making sure equal_to is case-insensitive