public Builder setHeader(
          com.google.cloud.tasks.v2beta3.HttpTarget.Header.Builder builderForValue) {
        if (headerBuilder_ == null) {
          header_ = builderForValue.build();
        } else {
          headerBuilder_.setMessage(builderForValue.build());
        }
        bitField0_ |= 0x00000001;
        onChanged();
        return this;
      }
<pre>
header embodying a key and a value.
</pre>

<code>.google.cloud.tasks.v2beta3.HttpTarget.Header header = 1;</code>
java-tasks/proto-google-cloud-tasks-v2beta3/src/main/java/com/google/cloud/tasks/v2beta3/HttpTarget.java