code: public SDVariable amean(SDVariable in, int... dimensions) {
          validateNumerical("amean", in);
          return amean(null, in, dimensions);
      }
docs: Absolute mean array reduction operation, optionally along specified dimensions: out = mean(abs(x))
  
  @param in         Input variable
  @param dimensions Dimensions to reduce over. If dimensions are not specified, full array reduction is performed
  @return Reduced array of rank (input rank - num dimensions)