@Test public void flattenHeaders_AnyGiven_ShouldReturnImmutableMap() { assertThrows(UnsupportedOperationException.class, () -> flattenHeaders(new HashMap<>()).put("k", "v")); }
public static Map<String, String> flattenHeaders(Map<String, List<String>> headers) { return flattenHeaders(headers, headerName -> true); }
HeaderUtils { public static Map<String, String> flattenHeaders(Map<String, List<String>> headers) { return flattenHeaders(headers, headerName -> true); } }
HeaderUtils { public static Map<String, String> flattenHeaders(Map<String, List<String>> headers) { return flattenHeaders(headers, headerName -> true); } private  HeaderUtils(); }
HeaderUtils { public static Map<String, String> flattenHeaders(Map<String, List<String>> headers) { return flattenHeaders(headers, headerName -> true); } private  HeaderUtils(); static Map<String, String> flattenHeaders(Map<String, List<String>> headers); static Map<String, String> flattenHeaders(Map<String, List<String>> headers,
			Predicate<String> headerNameFilter); static Map<String, List<String>> expandHeaders(Map<String, String> headers); }
HeaderUtils { public static Map<String, String> flattenHeaders(Map<String, List<String>> headers) { return flattenHeaders(headers, headerName -> true); } private  HeaderUtils(); static Map<String, String> flattenHeaders(Map<String, List<String>> headers); static Map<String, String> flattenHeaders(Map<String, List<String>> headers,
			Predicate<String> headerNameFilter); static Map<String, List<String>> expandHeaders(Map<String, String> headers);  }