code: public static INDArray sub(INDArray x, INDArray y, INDArray z, int... dimensions) {
          if(dimensions == null || dimensions.length == 0) {
              validateShapesNoDimCase(x,y,z);
              return Nd4j.getExecutioner().exec(new OldSubOp(x,y,z));
          }
  
          return Nd4j.getExecutioner().exec(new BroadcastSubOp(x,y,z,dimensions));
      }
docs: Broadcast subtraction op. See: {@link BroadcastSubOp}