code: protected void assertArgumentNotNull(String argumentName, Object value) {
          if (argumentName == null) {
              String msg = "The argument name should not be null: argName=null value=" + value;
              throw new IllegalArgumentException(msg);
          }
          if (value == null) {
              String msg = "The value should not be null: argName=" + argumentName;
              throw new IllegalArgumentException(msg);
          }
      }
docs: Assert that the argument is not null.
  @param argumentName The name of assert-target argument. (NotNull)
  @param value The value of argument. (NotNull)
  @throws IllegalArgumentException When the value is null.