Nothing is wrong with this function, yet FF won't run because it says there's an error in it:

import 'dart:convert';
import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:intl/intl.dart';
import 'package:timeago/timeago.dart' as timeago;
import '/flutter_flow/lat_lng.dart';
import '/flutter_flow/place.dart';
import '/flutter_flow/uploaded_file.dart';
import '/flutter_flow/custom_functions.dart';
import '/backend/backend.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import '/auth/firebase_auth/auth_util.dart';

double calculateSpeed(
  double lat1,
  double long1,
  double lat2,
  double long2,
) {
  /// MODIFY CODE ONLY BELOW THIS LINE

  // Convert degrees to radians
  lat1 = lat1 * pi / 180;
  long1 = long1 * pi / 180;
  lat2 = lat2 * pi / 180;
  long2 = long2 * pi / 180;

  double deltaLat = lat2 - lat1;
  double deltaLong = long2 - long1;
  double earthRadius = 6371; // Earth's radius in kilometers

  // Haversine formula
  double a = pow(sin(deltaLat / 2), 2) +
      cos(lat1) * cos(lat2) * pow(sin(deltaLong / 2), 2);
  double c = 2 * atan2(sqrt(a), sqrt(1 - a));
  double distance = earthRadius * c;

  // Assuming the time delta is 2 seconds, converting to hours
  double timeDeltaHours = 2 / 3600;
  double speed = distance / timeDeltaHours;

  return speed; // Speed in km/h
  /// MODIFY CODE ONLY ABOVE THIS LINE
}