docs: public Segment getSegment(SEGMENT_TYPE segmentType){
  
  		if(segmentType == null){
  			return null;
  		}		
  
  		if(segmentType == SEGMENT_TYPE.LINEAR){
  			return new LinearSegment();
  		} 
  		else if(segmentType == SEGMENT_TYPE.SPATIAL){
  			return new SpatialSegment();
  		} 
  		else if(segmentType == SEGMENT_TYPE.TEMPORAL){
  			return new TemporalSegment();
  		}
  		else if(segmentType == SEGMENT_TYPE.SPATIOTEMPORAL){
  			return new SpatioTemporalSegment();
  		}
  		
  		return null;
  	}