def is_edge_consistent(graph, u, v):
if not graph.has_edge(u, v):<EOL><INDENT>raise ValueError('<STR_LIT>'.format(graph, u, v))<EOL><DEDENT>return <NUM_LIT:0> == len(set(d[RELATION] for d in graph.edge[u][v].values()))<EOL>
Check if all edges between two nodes have the same relation.

    :param pybel.BELGraph graph: A BEL Graph
    :param tuple u: The source BEL node
    :param tuple v: The target BEL node
    :return: If all edges from the source to target node have the same relation
    :rtype: bool