code: public AbstractBooleanAssert<?> asBoolean() {
          isNotNull();
          boolean value = false;
          switch (actual.toLowerCase()) {
              case "true":
                  value = true;
                  break;
              case "false":
                  value = false;
                  break;
              default:
                  throwAssertionError(shouldBeConvertible(actual, "boolean"));
          }
  
          return AssertionsAdapter.assertThat(value);
      }
docs: Returns an {@code Assert} object that allows performing assertions on boolean value of the {@link String} under test.
  <p>
  If actual value after lowercasing is one of the following "true", "false", then it can be parsed to boolean.
  
  @throws AssertionError if the actual value is {@code null}.
  @throws AssertionError if the actual value does not contain a parsable boolean