public com.google.protobuf.ByteString getSourceBlueprintBytes() {
      java.lang.Object ref = sourceBlueprint_;
      if (ref instanceof String) {
        com.google.protobuf.ByteString b =
            com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
        sourceBlueprint_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
<pre>
Required. Immutable. The public blueprint ID from which this blueprint was
created.
</pre>

<code>
string source_blueprint = 3 [(.google.api.field_behavior) = REQUIRED, (.google.api.field_behavior) = IMMUTABLE];
</code>

@return The bytes for sourceBlueprint.
java-telcoautomation/proto-google-cloud-telcoautomation-v1alpha1/src/main/java/com/google/cloud/telcoautomation/v1alpha1/Blueprint.java