public Builder clearAttributes() {
          bitField0_ = (bitField0_ & ~0x00000002);
          attributes_ = null;
          if (attributesBuilder_ != null) {
            attributesBuilder_.dispose();
            attributesBuilder_ = null;
          }
          onChanged();
          return this;
        }
<pre>
A set of attributes on the annotation. You can have up to 4 attributes
per Annotation.
</pre>

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