'Constructs a Match object.
Args:
match_results: Integer tensor of shape [N] with (1) match_results[i]>=0,
meaning that column i is matched with row match_results[i].
(2) match_results[i]=-1, meaning that column i is not matched.
(3) match_results[i]=-2, meaning that column i is ignored.
Raises:
ValueError: if match_results does not have rank 1 or is not an
integer int32 scalar tensor'

def __init__(self, match_results):

    if (match_results.shape.ndims != 1):
        raise ValueError('match_results    should    have    rank    1')
    if (match_results.dtype != tf.int32):
        raise ValueError('match_results    should    be    an    int32    or    int64    scalar    tensor')
    self._match_results = match_results
