code: def qteSetAppletSignature(self, signature: str):
          
          if '*' in signature:
              raise QtmacsOtherError('The applet signature must not contain "*"')
  
          if signature == '':
              raise QtmacsOtherError('The applet signature must be non-empty')
  
          self._qteAdmin.appletSignature = signature
docs: Specify the applet signature.
  
          This signature is used by Qtmacs at run time to determine
          which macros are compatible with the apple. Macros have an
          identically called method so that Qtmacs can determine which
          macros are compatible with which applets. This method is
          typically called only in the applet constructor, but changing
          the macro signature at run time, is possible.
  
          The signature must be a non-empty string and not contain the
          '*' symbol.
  
          Note: the default signature is the class name as a string,
          eg. if the applet class is called MyAppClass, then the initial
          macro signature is the string 'MyAppClass'.
  
          |Args|
  
          * ``signature`` (**str**): the signature of this applet to
            determine compatible macros run time.
  
          |Returns|
  
          * **None**
  
          |Raises|
  
          * **QtmacsArgumentError** if at least one argument has an invalid type.
          * **QtmacsOtherError** if the signature is empty or contains
            the '*' wildcard symbol.