src/vs/editor/common/config/editorOptions.ts/EditorFloatOption/constructor
class EditorFloatOption:	constructor(id: K, name: PossibleKeyName<number>, defaultValue: number, validationFn: (value: number) => number, schema?: IConfigurationPropertySchema) {
		if (typeof schema !== 'undefined') {
			schema.type = 'number';
			schema.default = defaultValue;
		}
		super(id, name, defaultValue, schema);
		this.validationFn = validationFn;
	}