docs: def update(self, other):
          """ Merge two XmlCtsWorkMetadata Objects.
  
          - Original (left Object) keeps his parent.
          - Added document overwrite text if it already exists
  
          :param other: XmlCtsWorkMetadata object
          :type other: CtsWorkMetadata
          :return: XmlCtsWorkMetadata Object
          :rtype XmlCtsWorkMetadata:
          """
          if not isinstance(other, CtsWorkMetadata):
              raise TypeError("Cannot add %s to CtsWorkMetadata" % type(other))
          elif self.urn != other.urn:
              raise InvalidURN("Cannot add CtsWorkMetadata %s to CtsWorkMetadata %s " % (self.urn, other.urn))
  
          for urn, text in other.children.items():
              self.texts[urn] = text
              self.texts[urn].parent = self
              self.texts[urn].resource = None
  
          return self