public Builder mergeContext(com.google.cloud.vision.v1.ImageAnnotationContext value) {
      if (contextBuilder_ == null) {
        if (((bitField0_ & 0x00002000) != 0)
            && context_ != null
            && context_ != com.google.cloud.vision.v1.ImageAnnotationContext.getDefaultInstance()) {
          getContextBuilder().mergeFrom(value);
        } else {
          context_ = value;
        }
      } else {
        contextBuilder_.mergeFrom(value);
      }
      if (context_ != null) {
        bitField0_ |= 0x00002000;
        onChanged();
      }
      return this;
    }
<pre>
If present, contextual information is needed to understand where this image
comes from.
</pre>

<code>.google.cloud.vision.v1.ImageAnnotationContext context = 21;</code>
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/AnnotateImageResponse.java