public Builder clearIsSystemMessage() {
            bitField0_ &= ~0x00000040;
            isSystemMessage_ = false;
            onChanged();
            return this;
        }
<code>optional bool is_system_message = 7;</code>

@return This builder for chaining.
turms-server-common/src/main/java/im/turms/server/common/access/client/dto/model/message/Message.java