src/vs/workbench/api/common/extHostTypes.ts/Task/execution
class Task:	set execution(value: ProcessExecution | ShellExecution | CustomExecution | undefined) {
		if (value === null) {
			value = undefined;
		}
		this.clear();
		this._execution = value;
		const type = this._definition.type;
		if (Task.EmptyType === type || Task.ProcessType === type || Task.ShellType === type || Task.ExtensionCallbackType === type) {
			this.computeDefinitionBasedOnExecution();
		}
	}