public Builder mergeTime(com.google.protobuf.Timestamp value) {
        if (timeBuilder_ == null) {
          if (((bitField0_ & 0x00000001) != 0)
              && time_ != null
              && time_ != com.google.protobuf.Timestamp.getDefaultInstance()) {
            getTimeBuilder().mergeFrom(value);
          } else {
            time_ = value;
          }
        } else {
          timeBuilder_.mergeFrom(value);
        }
        if (time_ != null) {
          bitField0_ |= 0x00000001;
          onChanged();
        }
        return this;
      }
<pre>
The timestamp indicating the time the event occurred.
</pre>

<code>.google.protobuf.Timestamp time = 1;</code>
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/Span.java