public Builder mergeFrom(com.google.cloud.vertexai.api.Content other) {
      if (other == com.google.cloud.vertexai.api.Content.getDefaultInstance()) return this;
      if (!other.getRole().isEmpty()) {
        role_ = other.role_;
        bitField0_ |= 0x00000001;
        onChanged();
      }
      if (partsBuilder_ == null) {
        if (!other.parts_.isEmpty()) {
          if (parts_.isEmpty()) {
            parts_ = other.parts_;
            bitField0_ = (bitField0_ & ~0x00000002);
          } else {
            ensurePartsIsMutable();
            parts_.addAll(other.parts_);
          }
          onChanged();
        }
      } else {
        if (!other.parts_.isEmpty()) {
          if (partsBuilder_.isEmpty()) {
            partsBuilder_.dispose();
            partsBuilder_ = null;
            parts_ = other.parts_;
            bitField0_ = (bitField0_ & ~0x00000002);
            partsBuilder_ =
                com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders
                    ? getPartsFieldBuilder()
                    : null;
          } else {
            partsBuilder_.addAllMessages(other.parts_);
          }
        }
      }
      this.mergeUnknownFields(other.getUnknownFields());
      onChanged();
      return this;
    }
<pre>
The base structured datatype containing multi-part content of a message.

A `Content` includes a `role` field designating the producer of the `Content`
and a `parts` field containing multi-part data that contains the content of
the message turn.
</pre>

Protobuf type {@code google.cloud.vertexai.v1.Content}
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Content.java