code: def p_examples_add(self, p):
          'examples : examples example'
          p[0] = p[1]
          if p[2].label in p[0]:
              existing_ex = p[0][p[2].label]
              self.errors.append(
                  ("Example with label '%s' already defined on line %d." %
                   (existing_ex.label, existing_ex.lineno),
                   p[2].lineno, p[2].path))
          p[0][p[2].label] = p[2f p_examples_add(self, p):
          'examples : examples example'
          p[0] = p[1]
          if p[2].label in p[0]:
              existing_ex = p[0][p[2].label]
              self.errors.append(
                  ("Example with label '%s' already defined on line %d." %
                   (existing_ex.label, existing_ex.lineno),
                   p[2].lineno, p[2].path))
          p[0][p[2].label] = p[2]
docs: examples : examples example