code: def get_pyquery(self, tree=None, page_numbers=None):
          
          if not page_numbers:
              page_numbers = []
          if tree is None:
              if not page_numbers and self.tree is not None:
                  tree = self.tree
              else:
                  tree = self.get_tree(page_numbers)
          if hasattr(tree, 'getroot'):
              tree = tree.getroot()
          return PyQuery(tree, css_translator=PDFQueryTranslator())
docs: Wrap given tree in pyquery and return.
              If no tree supplied, will generate one from given page_numbers, or
              all page numbers.