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 URI.

The relative URI must begin with "/" and must be a valid HTTP relative URI.
It can contain a path and query string arguments.
If the relative URI 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_uri = 3;</code>

@return The bytes for relativeUri.
java-tasks/proto-google-cloud-tasks-v2beta3/src/main/java/com/google/cloud/tasks/v2beta3/AppEngineHttpRequest.java