code: @Nullable
    public static CSSDeclarationList readFromStream (@Nonnull final IHasInputStream aISP,
                                                     @Nonnull final Charset aCharset,
                                                     @Nonnull final ECSSVersion eVersion,
                                                     @Nullable final ICSSParseErrorHandler aCustomErrorHandler,
                                                     @Nullable final ICSSParseExceptionCallback aCustomExceptionHandler)
    {
      ValueEnforcer.notNull (aISP, "InputStreamProvider");
  
      final InputStream aIS = aISP.getInputStream ();
      if (aIS == null)
        return null;
      return readFromReader (StreamHelper.createReader (aIS, aCharset),
                             new CSSReaderSettings ().setCSSVersion (eVersion)
                                                     .setCustomErrorHandler (aCustomErrorHandler)
                                                     .setCustomExceptionHandler (aCustomExceptionHandler));
    }
docs: Read the CSS from the passed {@link IHasInputStream}.
  
  @param aISP
  The input stream provider to use. May not be <code>null</code>.
  @param aCharset
  The charset to be used. May not be <code>null</code>.
  @param eVersion
  The CSS version to use. May not be <code>null</code>.
  @param aCustomErrorHandler
  An optional custom error handler that can be used to collect the
  recoverable parsing errors. May be <code>null</code>.
  @param aCustomExceptionHandler
  An optional custom exception handler that can be used to collect the
  unrecoverable parsing errors. May be <code>null</code>.
  @return <code>null</code> if reading failed, the CSS declarations
  otherwise.