### Question:
HttpHeader implements Header { @Override public String toString() { return "HttpHeader: [" + "name='" + name + "'" + ", values=" + values + "]"; } HttpHeader(String name);  HttpHeader(String name, Collection<String> values); void value(String value); void clear(); Collection<String> values(); String name(); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString();  }### Answer:
@Test void headerToString_isNotNull() { HttpHeader httpHeader = new HttpHeader("X-Custom"); assertThat(httpHeader.toString()).isNotEmpty(); }