def one(nodes, or_none=False):
    """
    Assert that there is exactly one node in the give list, and return it.
    """
    if not nodes and or_none:
        return None
    assert len(
        nodes) == 1, 'Expected 1 result. Received %d results.' % (len(nodes))
    return nodes[0]
def one(nodes, or_none=False):
    
    if not nodes and or_none:
        return None
    assert len(
        nodes) == 1, 'Expected 1 result. Received %d results.' % (len(nodes))
    return nodes[0]
def one ( nodes , or_none = False ) : if not nodes and or_none : return None assert len ( nodes ) == 1 , 'Expected 1 result. Received %d results.' % ( len ( nodes ) ) return nodes [ 0 ]
Assert that there is exactly one node in the give list, and return it.
Assert that there is exactly one node in the give list and return it .