public Builder clearAnnotation() {
        if (annotationBuilder_ == null) {
          if (valueCase_ == 2) {
            valueCase_ = 0;
            value_ = null;
            onChanged();
          }
        } else {
          if (valueCase_ == 2) {
            valueCase_ = 0;
            value_ = null;
          }
          annotationBuilder_.clear();
        }
        return this;
      }
<pre>
Text annotation with a set of attributes.
</pre>

<code>.google.devtools.cloudtrace.v2.Span.TimeEvent.Annotation annotation = 2;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/Span.java