docs: public SDVariable convertToVariable(@NonNull SDVariable constant) {
          Preconditions.checkState(constant.dataType().isFPType(), "Only floating point SDVariables can be converted to variables," +
                  " datatype of %s is %s", constant.getVarName(), constant.dataType());
          convertToVariables(Collections.singletonList(constant));
          return constant;
      }