code: public SDVariable norm1(String name, SDVariable x, int... dimensions) {
          return norm1(name, x, false, dimensions);
      }
docs: Norm1 (L1 norm) reduction operation: The output contains the L1 norm for each tensor/subset along the specified dimensions:<br>
  out = sum_i abs(x[i])
  
  @param name       Output variable name
  @param x          Input variable
  @param dimensions dimensions to reduce over
  @return Output variable