code: public void assertNotEmpty(@Nullable Description description, @Nullable String actual) {
      assertNotNull(description, actual);
      if (actual.isEmpty()) {
        throw failures.failure(description, shouldNotBeEmpty());
      }
    }
docs: Asserts that the <em>actual</em> {@code String} is not empty.
  
  @param description the description of the <em>actual</em> {@code String}.
  @param actual the <em>actual</em> {@code String}.
  @throws AssertionError if the <em>actual</em> {@code String} is {@code null}.
  @throws AssertionError if the <em>actual</em> {@code String} is empty.