во время записи данных на график в Graphview, получая дополнительную строку. как я могу решить это?

Question

Я пытаюсь нанести данные в GraphView, пока я получаю дополнительную линию, начинающую график.

В используемом пакете com.jjoe64.graphview.GraphView

Мой код:

public class ABIModeActivity extends AppCompatActivity {

private LineGraphSeries<DataPoint> mSeries2;
private double graph2LastXValue = 5d;
static GraphView graph2;
Context context;
Button okbutton;
CountDownTimer cTimer = null;
int i=0;
int[] BP_Data=new int[]{115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,115,113,105,76,36,7,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,7,33,73,105,112,114,113,84,32,22,5,1,0,0,0,0,0,1,8,37,76,95,112,111,90,51,12,2,0,0,0,0,2,21,59,83,105,113,112,105,62,48,17,2,7,33,73,105,112,114,113,84,32,22,5,1,0,0,0,0,0,1,8,37,76,95,112,111,90,51,12,2,0,2,21,59,83,105,113,112,105,62,48,17,2,2,21,59,83,105,113,112,105,62,48,17,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getSupportActionBar().hide();
    setContentView(R.layout.activity_abimode);

    //I'm using Timer to simulate the live data graph which I'm getting in my actual device.
    //Timer is used only for simulation of live data
    cTimer = new CountDownTimer(100000, 20) {
        public void onTick(long millisUntilFinished) {
            graph2LastXValue += 1d;
            drawgraph(graph2LastXValue,BP_Data[i]);
            i++;
            if(i==180){
                cTimer.cancel();//Stop the live graph plotting when it reached the end of data
                i=0;
            }
        }
        public void onFinish() {

        }
    };

    okbutton =(Button) findViewById(R.id.okbutton);
    okbutton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view)
        {
            cTimer.start();// to start plotting the graph data with the timer
        }
    });
    //Actuall graph realted code starting
    graph2 = (GraphView) findViewById(R.id.graph2);
    mSeries2 = new LineGraphSeries<>();
    mSeries2.setThickness(3);
    graph2.getViewport().setXAxisBoundsManual(true);
    graph2.getViewport().setYAxisBoundsManual(true);
    graph2.getViewport().setMinX(0);
    graph2.getViewport().setMaxX(200);
    graph2.getViewport().setMinY(0);
    graph2.getViewport().setMaxY(251);
    graph2.getGridLabelRenderer().setTextSize(0);
    graph2.getViewport().setScrollable(true); // enables horizontal scrolling
    graph2.getViewport().setScrollableY(true); // enables vertical scrolling
    graph2.getViewport().setDrawBorder(false);
    graph2.getViewport().setBackgroundColor(Color.TRANSPARENT);
    graph2.addSeries(mSeries2);
    context = this;
}

public void drawgraph(Double graphvalue,int incrementValue)//plotting the value in the graph
{
    mSeries2.appendData(new DataPoint(graphvalue, incrementValue), true, 200);
}
}

Почему эта дополнительная линия идет? И как я могу это решить?