code: public void assertNotLessThan(Description description, Character actual, char other) {
      assertNotNull(description, actual);
      if (isLessThan(actual, other)) {
        throw failures.failure(description, ShouldNotBeLessThan.shouldNotBeLessThan(actual, other));
      }
    }
docs: Asserts that the actual value is greater than or equal to the other one.
  
  @param description contains information about the assertion.
  @param actual the actual value.
  @param other the value to compare the actual value to.
  @throws AssertionError if the actual value is {@code null}.
  @throws AssertionError if the actual value is less than the other one.