Cant get fitBounds to work - google-maps

Question

I'm not sure where to include the fit bounds as no matter where I put it, the map is centered on where initMap specifies which is halfway across the world instead of where the markers are.
Calls is just an object array that stores sets of lat/lngs
function initMap()
{
map = new google.maps.Map(document.getElementById('map'),
{
center: { lat: -34.397, lng: 150.644 },
zoom: 12,
scaleControl: true
});
}
// Place Markers on Map
function initMarkers()
{
for (var i = 0; i < Calls.length; i++)
{
var marker = new google.maps.Marker({
position: Calls[i],
map: map
});
}
}
function fit()
{
var bound = new google.maps.LatLngBounds();
for (var i in Calls)
{
bound.extend(Calls[i].getPosition());
}
map.fitBounds(bound);
}
// Initialize GoogleMap on Page Load
window.onload = function()
{
initMap();
initMarkers();
fit();
}

Answer 1

The posted code generates a javascript error (not the one originally reported in the question, but that has been removed): Uncaught TypeError: Calls[i].getPosition is not a function. Calls is an array of objects, so it won't have a .getPosition method.
function fit()
{
var bound = new google.maps.LatLngBounds();
for (var i in Calls)
{
bound.extend(new google.maps.LatLng(Calls[i].lat,Calls[i].lng));
}
map.fitBounds(bound);
}
code snippet:
var Calls = [{
lat: 42,
lng: -72
}, {
lat: 40.7127837,
lng: -74.0059413
}, {
lat: 40.735657,
lng: -74.1723667
}];
function initMap() {
map = new google.maps.Map(document.getElementById('map'), {
center: {
lat: -34.397,
lng: 150.644
},
zoom: 12,
scaleControl: true
});
}
// Place Markers on Map
function initMarkers() {
for (var i = 0; i < Calls.length; i++) {
var marker = new google.maps.Marker({
position: Calls[i],
map: map
});
}
}
function fit() {
var bound = new google.maps.LatLngBounds();
for (var i in Calls) {
bound.extend(new google.maps.LatLng(Calls[i].lat, Calls[i].lng));
}
map.fitBounds(bound);
}
// Initialize GoogleMap on Page Load
window.onload = function() {
initMap();
initMarkers();
fit();
}
html,
body,
#map {
height: 100%;
width: 100%;
margin: 0px;
padding: 0px
}
<script src="https://maps.googleapis.com/maps/api/js"></script>
<div id="map"></div>