code: def insert_attribute(self, att, index):
          
          javabridge.call(self.jobject, "insertAttributeAt", "(Lweka/core/Attribute;I)V", att.jobject, index)
docs: Inserts the attribute at the specified location.
  
          :param att: the attribute to insert
          :type att: Attribute
          :param index: the index to insert the attribute at
          :type index: int