public Builder setContentBytes(com.google.protobuf.ByteString value) {
            copyOnWrite();
            instance.setContentBytes(value);
            return this;
        }
<code>optional string content = 3;</code>

@param value The bytes for content to set.
@return This builder for chaining.
turms-client-kotlin/src/main/java/im/turms/client/model/proto/model/group/GroupJoinRequest.java