isBoundFunctionExpression = expr => {
	if (expr.type !== "CallExpression") return false;
	if (expr.callee.type !== "MemberExpression") return false;
	if (expr.callee.computed) return false;
	if (expr.callee.object.type !== "FunctionExpression") return false;
	if (expr.callee.property.type !== "Identifier") return false;
	if (expr.callee.property.name !== "bind") return false;
	return true;
}
@param {Expression | SpreadElement} expr expression
@returns {expr is CallExpression} true if it's a bound function expression