def onnx_get_input_nodes(graph, node):
    """ 
    Return all nodes that are inputs for a node 

    Parameters
    ----------
    graph : ONNX GraphProto
        Specifies a GraphProto object.
    node : ONNX NodeProto
        Specifies a NodeProto object.

    Returns
    -------
    list
        list of NodeProto
    
    """
    in_nodes = []
    for i in node.input:
        for n in graph.node:
            if i in n.output:
                in_nodes.append(n)
    return in_nodes
