public double exactArea(){
  S2Point v0=getVertex(0);
  S2Point v1=getVertex(1);
  S2Point v2=getVertex(2);
  S2Point v3=getVertex(3);
  return S2.area(v0,v1,v2) + S2.area(v0,v2,v3);
}

public double exactArea ( ) { S2Point v0 = getVertex ( 0 ) ; S2Point v1 = getVertex ( 1 ) ; S2Point v2 = getVertex ( 2 ) ; S2Point v3 = getVertex ( 3 ) ; return S2 . area ( v0 , v1 , v2 ) + S2 . area ( v0 , v2 , v3 ) ; }
return the area of this cell as accurately as possible . this method is more expensive but it is accurate to 6 digits of precision even for leaf cells ( whose area is approximately 1e - 18 ) .
