### Question:
ImmutableCharacterEncoding implements CharacterEncoding { @Override public Charset charset() { return this.charset; } ImmutableCharacterEncoding(Charset charset); @Override boolean isWildcard(); @Override String name(); @Override Charset charset(); @Override String toHeader(); @Override int hashCode(); @Override boolean equals(Object obj); @Override String toString();  }### Answer:
@Test public void wildcardCharacterEncodingHasNullCharset() throws Exception { assertThat(wildcard().charset(),nullValue()); }
@Test public void regularCharacterEncodingExposesItCharset() throws Exception { assertThat(regular().charset(),equalTo(StandardCharsets.UTF_8)); }