docs: def copy_to (self, dest, preserve='mode'):
          """Copy this path — as a file — to another *dest*.
  
          The *preserve* argument specifies which meta-properties of the file
          should be preserved:
  
          ``none``
            Only copy the file data.
          ``mode``
            Copy the data and the file mode (permissions, etc).
          ``all``
            Preserve as much as possible: mode, modification times, etc.
  
          The destination *dest* may be a directory.
  
          Returns the final destination path.
  
          """
          # shutil.copyfile() doesn't let the destination be a directory, so we
          # have to manage that possibility ourselves.
  
          import shutil
          dest = Path (dest)
  
          if dest.is_dir ():
              dest = dest / self.name
  
          if preserve == 'none':
              shutil.copyfile (str(self), str(dest))
          elif preserve == 'mode':
              shutil.copy (str(self), str(dest))
          elif preserve == 'all':
              shutil.copy2 (str(self), str(dest))
          else:
              raise ValueError ('unrecognized "preserve" value %r' % (preserve,))
  
          return dest