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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _cnn_filter(in_file, vrn_files, data):
 """Perform CNN filtering on input VCF using pre-trained models. """

    #tensor_type = "reference"  # 1D, reference sequence
    tensor_type = "read_tensor"  # 2D, reads, flags, mapping quality
    score_file = _cnn_score_variants(in_file, tensor_type, data)
    return _cnn_tranch_filtering(score_file, vrn_files, tensor_type, data)