def _VisitSchema(self, schema, func):
    """Visit a schema tree, calling a function on every child.

    Args:
      schema: (Schema) The Schema to visit.
      func: (function) Method to call on each object.
    """
    func(schema)
    func(schema.module)
    for prop in schema.values.get('properties', []):
      func(prop)
    for child in self.children:
      func(child)