'Traverses the tree, stripping out whitespace until text data is found
:param node: The node to strip
:return: True if non-whitespace data was found, False otherwise'

def _lstrip(self, node):

    for child in node.children:
        if isinstance(child, DataNode):
            child.lstrip()
            if child.data:
                return True
        else:
            found = self._lstrip(child)
            if found:
                return True
    return False
