lib/Ext/core/class/Loader.js
function(name, value) {
            if (Ext.isObject(name) && arguments.length === 1) {
                Ext.merge(this.config, name);
            }
            else {
                this.config[name] = (Ext.isObject(value)) ? Ext.merge(this.config[name], value) : value;
            }
            setPathCount += 1;
            return this;
        }
function(name, value) {
            if (Ext.isObject(name) && arguments.length === 1) {
                Ext.merge(this.config, name);
            }
            else {
                this.config[name] = (Ext.isObject(value)) ? Ext.merge(this.config[name], value) : value;
            }
            setPathCount += 1;
            return this;
        }
Set the configuration for the loader. This should be called right after ext-(debug).js
is included in the page, and before Ext.onReady. i.e:

<script type="text/javascript" src="ext-core-debug.js"></script>
<script type="text/javascript">
Ext.Loader.setConfig({
enabled: true,
paths: {
'My': 'my_own_path'
}
});
<script>
<script type="text/javascript">
Ext.require(...);

Ext.onReady(function() {
// application code here
});
</script>

Refer to config options of {@link Ext.Loader} for the list of possible properties.

@param {Object/String} name The config object to override the default values
or name of a single config setting when also passing the second parameter.
@param {Mixed} [value] The value for the config setting.
@return {Ext.Loader} this