code: public static <T> Expression<T> set(Path<T> target, Expression<? extends T> value) {
          if (value != null) {
              return Expressions.operation(target.getType(), SQLOps.SET_PATH, target, value);
          } else {
              return Expressions.operation(target.getType(), SQLOps.SET_LITERAL,
                      target, Expressions.nullExpression());
          }
  
      }
docs: Create an assignment expression
  
  @param target target expression
  @param value value to be set
  @param <T>
  @return target = value