# File lib/celerity/elements/text_field.rb, line 107
    def contains_text(expected_text)
      assert_exists

      case expected_text
      when Regexp
        value() =~ expected_text
      when String
        value().index(expected_text)
      else
        raise TypeError, "expected String or Regexp, got #{expected_text.inspect}:#{expected_text.class}"
      end
    end