code: def build_person(self, doc, entity):
          
          match = self.person_re.match(entity)
          if match and validations.validate_person_name(match.group(self.PERSON_NAME_GROUP)):
              name = match.group(self.PERSON_NAME_GROUP).strip()
              email = match.group(self.PERSON_EMAIL_GROUP)
              if (email is not None) and (len(email) != 0):
                  return creationinfo.Person(name=name, email=email.strip())
              else:
                  return creationinfo.Person(name=name, email=None)
          else:
              raise SPDXValueError('Failed to extract person name')
docs: Builds an organization object of of a string representation.
          Returns built organization. Raises SPDXValueError if failed to extract
          name.