code: def copy_w_ext(srcfile, destdir, basename):
      
  
      ext = get_extension(op.basename(srcfile))
  
      dstpath = op.join(destdir, basename + ext)
  
      return copy_w_plus(srcfile, dstpath)
docs: Copy `srcfile` in `destdir` with name `basename + get_extension(srcfile)`.
      Add pluses to the destination path basename if a file with the same name already
      exists in `destdir`.
  
      Parameters
      ----------
      srcfile: str
  
      destdir: str
  
      basename:str
  
      Returns
      -------
      dstpath: str