private com.google.protobuf.MapField<java.lang.String, java.lang.String> internalGetHeaders() {
    if (headers_ == null) {
      return com.google.protobuf.MapField.emptyMapField(HeadersDefaultEntryHolder.defaultEntry);
    }
    return headers_;
  }
<pre>
The relative URL.

The relative URL must begin with "/" and must be a valid HTTP relative URL.
It can contain a path and query string arguments.
If the relative URL is empty, then the root path "/" will be used.
No spaces are allowed, and the maximum length allowed is 2083 characters.
</pre>

<code>string relative_url = 3;</code>

@return The bytes for relativeUrl.
java-tasks/proto-google-cloud-tasks-v2beta2/src/main/java/com/google/cloud/tasks/v2beta2/AppEngineHttpRequest.java