docs: @Override
      public void typeSystemInit(TypeSystem typeSystem) throws AnalysisEngineProcessException {
  
          // sentence type
          this.sentenceType = AnnotatorUtil.getRequiredTypeParameter(this.context, typeSystem,
                          UimaUtil.SENTENCE_TYPE_PARAMETER);
  
          // token type
          this.tokenType = AnnotatorUtil.getRequiredTypeParameter(this.context, typeSystem,
                          UimaUtil.TOKEN_TYPE_PARAMETER);
  
          // pos feature
          this.posFeature = AnnotatorUtil.getRequiredFeatureParameter(this.context, this.tokenType,
                          UimaUtil.POS_FEATURE_PARAMETER, CAS.TYPE_NAME_STRING);
  
          this.probabilityFeature = AnnotatorUtil.getOptionalFeatureParameter(this.context, this.tokenType,
                          UimaUtil.PROBABILITY_FEATURE_PARAMETER, CAS.TYPE_NAME_DOUBLE);
      }