public TextDocumentConverter(IFeatureVectorFactory featureVectorFactory)
 {
     this.featureVectorFactory = featureVectorFactory;
 }
 public ProblemConverter(ITextPreprocessor textPreprocessor, IFeatureVectorFactory featureVectorFactory, ITagConverter tagConverter)
 {
     this.textPreprocessor = textPreprocessor;
     this.featureVectorFactory = featureVectorFactory;
     this.tagConverter = tagConverter;
 }