    const close = () => {
      this.close(handle, (er) => {
        if (size === 0) {
          // Collect the data into the buffers list.
          // TODO: replace `Buffer.concat()`
          buffer = Buffer.concat(buffers, pos);
        } else if (pos < size) {
          buffer = bufferSlice(buffer, 0, pos);
        }

        if (encoding)
          buffer = buffer.toString(encoding);
        return callback && callback(er, buffer);
      });
    };
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.