public Builder removeLabels(java.lang.String key) {
      if (key == null) {
        throw new NullPointerException("map key");
      }
      internalGetMutableLabels().getMutableMap().remove(key);
      return this;
    }
<pre>
Collection of labels associated with the span. Label keys must be less than
128 bytes. Label values must be less than 16 kilobytes (10MB for
`/stacktrace` values).

Some predefined label keys exist, or you may create your own. When creating
your own, we recommend the following formats:

* `/category/product/key` for agents of well-known products (e.g.
  `/db/mongodb/read_size`).
* `short_host/path/key` for domain-specific keys (e.g.
  `foo.com/myproduct/bar`)

Predefined labels include:

*   `/agent`
*   `/component`
*   `/error/message`
*   `/error/name`
*   `/http/client_city`
*   `/http/client_country`
*   `/http/client_protocol`
*   `/http/client_region`
*   `/http/host`
*   `/http/method`
*   `/http/path`
*   `/http/redirected_url`
*   `/http/request/size`
*   `/http/response/size`
*   `/http/route`
*   `/http/status_code`
*   `/http/url`
*   `/http/user_agent`
*   `/pid`
*   `/stacktrace`
*   `/tid`
</pre>

<code>map&lt;string, string&gt; labels = 7;</code>
java-trace/proto-google-cloud-trace-v1/src/main/java/com/google/devtools/cloudtrace/v1/TraceSpan.java