_decompress(data, fin, callback) {
    const endpoint = this._isServer ? 'client' : 'server';

    if (!this._inflate) {
      const key = `${endpoint}_max_window_bits`;
      const windowBits =
        typeof this.params[key] !== 'number'
          ? zlib.Z_DEFAULT_WINDOWBITS
          : this.params[key];

      this._inflate = zlib.createInflateRaw({
        ...this._options.zlibInflateOptions,
        windowBits
      });
      this._inflate[kPerMessageDeflate] = this;
      this._inflate[kTotalLength] = 0;
      this._inflate[kBuffers] = [];
      this._inflate.on('error', inflateOnError);
      this._inflate.on('data', inflateOnData);
    }

    this._inflate[kCallback] = callback;

    this._inflate.write(data);
    if (fin) this._inflate.write(TRAILER);

    this._inflate.flush(() => {
      const err = this._inflate[kError];

      if (err) {
        this._inflate.close();
        this._inflate = null;
        callback(err);
        return;
      }

      const data = bufferUtil.concat(
        this._inflate[kBuffers],
        this._inflate[kTotalLength]
      );

      if (this._inflate._readableState.endEmitted) {
        this._inflate.close();
        this._inflate = null;
      } else {
        this._inflate[kTotalLength] = 0;
        this._inflate[kBuffers] = [];

        if (fin && this.params[`${endpoint}_no_context_takeover`]) {
          this._inflate.reset();
        }
      }

      callback(null, data);
    });
  }
Decompress data.

@param {Buffer} data Compressed data
@param {Boolean} fin Specifies whether or not this is the last fragment
@param {Function} callback Callback
@private