code: def p_file_contrib_1(self, p):
          
          try:
              if six.PY2:
                  value = p[2].decode(encoding='utf-8')
              else:
                  value = p[2]
              self.builder.add_file_contribution(self.document, value)
          except OrderError:
              self.order_error('FileContributor', 'FileName', p.lineno(1))
docs: file_contrib : FILE_CONTRIB LINE