code: public static String getNameWithoutExtension(String file) {
          N.checkArgNotNull(file);
  
          String fileName = new File(file).getName();
          int dotIndex = fileName.lastIndexOf('.');
          return (dotIndex == -1) ? fileName : fileName.substring(0, dotIndex);
      }
docs: Note: copied from Google Guava under Apache License v2.
  
  Returns the file name without its
  <a href="http://en.wikipedia.org/wiki/Filename_extension">file extension</a> or path. This is
  similar to the {@code basename} unix command. The result does not include the '{@code .}'.
  
  @param file The name of the file to trim the extension from. This can be either a fully
  qualified file name (including a path) or just a file name.
  @return The file name without its path or extension.
  @since 14.0