code: def xml(self, fn=None, src='word/document.xml', XMLClass=XML, **params):
          "return the src with the given transformation applied, if any."
          if src in self.xml_cache: return self.xml_cache[src]
          if src not in self.zipfile.namelist(): return
          x = XMLClass(
                  fn=fn or (self.fn and self.fn.replace('.docx', '.xml')) or None,
                  root=self.zipfile.read(src))
          self.xml_cache[src] = x
          return f xml(self, fn=None, src='word/document.xml', XMLClass=XML, **params):
          "return the src with the given transformation applied, if any."
          if src in self.xml_cache: return self.xml_cache[src]
          if src not in self.zipfile.namelist(): return
          x = XMLClass(
                  fn=fn or (self.fn and self.fn.replace('.docx', '.xml')) or None,
                  root=self.zipfile.read(src))
          self.xml_cache[src] = x
          return x
docs: return the src with the given transformation applied, if any.