How to use the graceful-fs.closeSync function in graceful-fs

function findAccessibleSync (logprefix, dir, candidates) {
  for (var next = 0; next < candidates.length; next++) {
    var candidate = path.resolve(dir, candidates[next])
    try {
      var fd = fs.openSync(candidate, 'r')
    } catch (e) {
      // this candidate was not found or not readable, do nothing
      log.silly(logprefix, 'Could not open %s: %s', candidate, e.message)
      continue
    }
    fs.closeSync(fd)
    log.silly(logprefix, 'Found readable %s', candidate)
    return candidate
  }

  return undefined
}

const _buff = require('../util/buffer')(BUF_LENGTH)

  const fdr = fs.openSync(src, 'r')
  const fdw = fs.openSync(dest, 'w', srcStat.mode)
  let pos = 0

  while (pos < srcStat.size) {
    const bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  if (opts.preserveTimestamps) fs.futimesSync(fdw, srcStat.atime, srcStat.mtime)

  fs.closeSync(fdr)
  fs.closeSync(fdw)
}

const stat = fs.fstatSync(fdr)
  const fdw = fs.openSync(destFile, 'w', stat.mode)
  let bytesRead = 1
  let pos = 0

  while (bytesRead > 0) {
    bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  if (preserveTimestamps) {
    fs.futimesSync(fdw, stat.atime, stat.mtime)
  }

  fs.closeSync(fdr)
  fs.closeSync(fdw)
}

const fdr = fs.openSync(src, 'r')
  const fdw = fs.openSync(dest, 'w', srcStat.mode)
  let bytesRead = 1
  let pos = 0

  while (bytesRead > 0) {
    bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  if (opts.preserveTimestamps) fs.futimesSync(fdw, srcStat.atime, srcStat.mtime)

  fs.closeSync(fdr)
  fs.closeSync(fdw)
}

const BUF_LENGTH = 64 * 1024
  const _buff = require('../util/buffer')(BUF_LENGTH)

  const fdr = fs.openSync(src, 'r')
  const fdw = fs.openSync(dest, 'w', srcStat.mode)
  let pos = 0

  while (pos < srcStat.size) {
    const bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  if (opts.preserveTimestamps) fs.futimesSync(fdw, srcStat.atime, srcStat.mtime)

  fs.closeSync(fdr)
  fs.closeSync(fdw)
}

const flags = overwrite ? 'w' : 'wx'

  const fdr = fs.openSync(src, 'r')
  const stat = fs.fstatSync(fdr)
  const fdw = fs.openSync(dest, flags, stat.mode)
  let bytesRead = 1
  let pos = 0

  while (bytesRead > 0) {
    bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  fs.closeSync(fdr)
  fs.closeSync(fdw)
  return fs.unlinkSync(src)
}

const fdw = fs.openSync(destFile, 'w', stat.mode)
  let bytesRead = 1
  let pos = 0

  while (bytesRead > 0) {
    bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  if (preserveTimestamps) {
    fs.futimesSync(fdw, stat.atime, stat.mtime)
  }

  fs.closeSync(fdr)
  fs.closeSync(fdw)
}

const flags = overwrite ? 'w' : 'wx'

  const fdr = fs.openSync(src, 'r')
  const stat = fs.fstatSync(fdr)
  const fdw = fs.openSync(dest, flags, stat.mode)
  let bytesRead = 1
  let pos = 0

  while (bytesRead > 0) {
    bytesRead = fs.readSync(fdr, _buff, 0, BUF_LENGTH, pos)
    fs.writeSync(fdw, _buff, 0, bytesRead)
    pos += bytesRead
  }

  fs.closeSync(fdr)
  fs.closeSync(fdw)
  return fs.unlinkSync(src)
}