PLEASE, help me

[jcosta191]

Launching lib\main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...
Resolving dependencies...
Running Gradle task 'assembleDebug'...

Compiler message:
lib/fragments/startrequest.dart:41:37: Error: The method 'listen' isn't defined for the class 'Stream Function()'.

• 'Stream' is from 'dart:async'.
• 'LocationData' is from 'package:location/location.dart' ('file:///C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/location-2.3.5/lib/location.dart').
  Try correcting the name to the name of an existing method, or defining a method named 'listen'.
  _location.onLocationChanged.listen((Map<String, double> result) {
  ^^^^^^
  lib/fragments/startrequest.dart:54:18: Error: A value of type 'Future Function()' can't be assigned to a variable of type 'Map<String, double>'.
• 'Future' is from 'dart:async'.
• 'LocationData' is from 'package:location/location.dart' ('file:///C:/src/flutter/.pub-cache/hosted/pub.dartlang.org/location-2.3.5/lib/location.dart').
• 'Map' is from 'dart:core'.
  Try changing the type of the left hand side, or casting the right hand side to 'Map<String, double>'.
  location = await _location.getLocation;
  ^
  Compiler failed on C:\Users\johnn\AndroidStudioProjects\flutter_app-master\lib\main.dart
  Finished with error: Gradle task assembleDebug failed with exit code 1