code: @Nonnull
    public SchematronResourcePure setErrorHandler (@Nullable final IPSErrorHandler aErrorHandler)
    {
      if (m_aBoundSchema != null)
        throw new IllegalStateException ("Schematron was already bound and can therefore not be altered!");
      m_aErrorHandler = aErrorHandler;
      return this;
    }
docs: Set the error handler to be used during binding.
  
  @param aErrorHandler
  The error handler. May be <code>null</code>.
  @return this