public boolean updateValue(@Nullable TraceContext context, @Nullable String value) {
    if (context == null) return false;
    if (this.context.updateValue(this, context, value)) {
      CorrelationFlushScope.flush(this, value);
      return true;
    }
    return false;
  }
@Test void updateValue_context_null() {
    // permits unguarded use of CurrentTraceContext.get()
    REQUEST_ID.updateValue((TraceContext) null, null);
  }