lib/HalDependencyResolver.js
function(deviceModules, firmwareModule) {
		var safeDeviceModules = this._repairDescribeErrors(deviceModules);
		var safeModuleRequires = firmwareModule.toDescribe();
		
		return this._walkChain(safeDeviceModules, safeModuleRequires);
	}
function(deviceModules, firmwareModule) {
		var safeDeviceModules = this._repairDescribeErrors(deviceModules);
		var safeModuleRequires = firmwareModule.toDescribe();
		
		return this._walkChain(safeDeviceModules, safeModuleRequires);
	}
/*
given what modules are 'described' as being on a device,
and known firmware module info, figure out which modules need
to be updated on the device.

@param deviceModules
@param firmwareModule