public Builder setAttributes(com.google.devtools.cloudtrace.v2.Span.Attributes value) {
      if (attributesBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        attributes_ = value;
      } else {
        attributesBuilder_.setMessage(value);
      }
      bitField0_ |= 0x00000040;
      onChanged();
      return this;
    }
<pre>
A set of attributes on the span. You can have up to 32 attributes per
span.
</pre>

<code>.google.devtools.cloudtrace.v2.Span.Attributes attributes = 7;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/Span.java