/guava/guava/src/com/google/common/math/LinearTransformation.java
checkArgument( isFinite( y1) && isFinite( y2) ) ;
checkArgument ( isFinite ( x2 ) && isFinite ( y2 ) ) ;
private final double y1; private LinearTransformationBuilder(double x1, double y1) { this.x1 = x1; this.y1 = y1; } public LinearTransformation and(double x2, double y2) { <extra_id_0> if (x2 == x1) { checkArgument(y2 != y1); return new VerticalLinearTransformation(x1); } else { return withSlope((y2 - y1) / (x2 - x1)); }