code: public void assertEqual(Description description, Character actual, char expected) {
      assertNotNull(description, actual);
      if (actual.charValue() != expected) {
        throw failures.failure(description, shouldBeEqual(actual, expected));
      }
    }
docs: Asserts that two characters are equal.
  
  @param description contains information about the assertion.
  @param actual the actual value.
  @param expected the expected value.
  @throws AssertionError if the actual value is {@code null}.
  @throws AssertionError if the actual value is not equal to the expected one. This method will throw a
  {@code org.junit.ComparisonFailure} instead if JUnit is in the classpath and the expected and actual
  values are not equal.