@Override
  public void setNumber( double number ) {
    this.string = "" + number;
  }
@Test
  public void testSetNumber() {
    ValueString vs = new ValueString();

    vs.setNumber( 0 );
    assertEquals( "0.0", vs.getString() );
    vs.setNumber( 1 );
    assertEquals( "1.0", vs.getString() );
    vs.setNumber( -1 );
    assertEquals( "-1.0", vs.getString() );
    vs.setNumber( 2.5 );
    assertEquals( "2.5", vs.getString() );
    vs.setNumber( 2.8 );
    assertEquals( "2.8", vs.getString() );
  }