How to use the d3-interpolate.interpolateRound function in d3-interpolate

iKeyVal = d3Interpolate.interpolate({ x: 0, y: 1 }, { x: 1, y: 10, z: 100 });

d3Interpolate.interpolate(new NumCoercible(1), new NumCoercible(5));
d3Interpolate.interpolate({ a: 1 }, new NumCoercible(5));

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateNumber(0, 100);
iNum = d3Interpolate.interpolateNumber(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateRound(0, 100);
iNum = d3Interpolate.interpolateRound(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateString(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateString('-1', '2');
str = iString(0.5);

// test interpolateDate(a, b) signature ----------------------------------------------------

iDate = d3Interpolate.interpolateDate(new Date(2016, 6, 1), new Date(2016, 6, 31));

// test interpolateArray(a, b) signature ----------------------------------------------------

iArrayNum = d3Interpolate.interpolateArray>([1, 2], [4, 8]); // explicit typing
arrNum = iArrayNum(0.5);

// Key Value

iKeyVal = d3Interpolate.interpolate({ x: 0, y: 1 }, { x: 1, y: 10, z: 100 });

d3Interpolate.interpolate(new NumCoercible(1), new NumCoercible(5));
d3Interpolate.interpolate({ a: 1 }, new NumCoercible(5));

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateNumber(0, 100);
iNum = d3Interpolate.interpolateNumber(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateRound(0, 100);
iNum = d3Interpolate.interpolateRound(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateString(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateString('-1', '2');
str = iString(0.5);

// test interpolateDate(a, b) signature ----------------------------------------------------

iDate = d3Interpolate.interpolateDate(new Date(2016, 6, 1), new Date(2016, 6, 31));

// test interpolateArray(a, b) signature ----------------------------------------------------

iArrayNum = d3Interpolate.interpolateArray>([1, 2], [4, 8]); // explicit typing
arrNum = iArrayNum(0.5);

// Key Value

iKeyVal = d3Interpolate.interpolate({ x: 0, y: 1 }, { x: 1, y: 10, z: 100 });

d3Interpolate.interpolate(new NumCoercible(1), new NumCoercible(5));
d3Interpolate.interpolate({ a: 1 }, new NumCoercible(5));

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateNumber(0, 100);
iNum = d3Interpolate.interpolateNumber(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateRound(0, 100);
iNum = d3Interpolate.interpolateRound(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateString(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateString('-1', '2');
str = iString(0.5);

// test interpolateDate(a, b) signature ----------------------------------------------------

iDate = d3Interpolate.interpolateDate(new Date(2016, 6, 1), new Date(2016, 6, 31));

// test interpolateArray(a, b) signature ----------------------------------------------------

iArrayNum = d3Interpolate.interpolateArray([1, 2], [4, 8]); // explicit typing
arrNum = iArrayNum(0.5);

iKeyVal = d3Interpolate.interpolate({ x: 0, y: 1 }, { x: 1, y: 10, z: 100 });

d3Interpolate.interpolate(new NumCoercible(1), new NumCoercible(5));
d3Interpolate.interpolate({ a: 1 }, new NumCoercible(5));

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateNumber(0, 100);
iNum = d3Interpolate.interpolateNumber(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateNumber(a, b) signature ----------------------------------------------------

iNum = d3Interpolate.interpolateRound(0, 100);
iNum = d3Interpolate.interpolateRound(new NumCoercible(0), new NumCoercible(100));
num = iNum(0.5);

// test interpolateString(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateString('-1', '2');
str = iString(0.5);

// test interpolateDate(a, b) signature ----------------------------------------------------

iDate = d3Interpolate.interpolateDate(new Date(2016, 6, 1), new Date(2016, 6, 31));

// test interpolateArray(a, b) signature ----------------------------------------------------

iArrayNum = d3Interpolate.interpolateArray([1, 2], [4, 8]); // explicit typing
arrNum = iArrayNum(0.5);