code: def get_child_nodes(docgraph, parent_node_id, data=False):
      
      return select_neighbors_by_edge_attribute(
          docgraph=docgraph,
          source=parent_node_id,
          attribute='edge_type',
          value=[EdgeTypes.dominance_relation],
          data=data)
docs: Yield all nodes that the given node dominates or spans.