False positive for unnecessary_lambdas

[davidmorgan]

  int count(String s) => s.length;
  final strings = ['a', 'bb', 'ccc', 'dddd'];
  final map = Map<String, int>.fromIterable(strings, value: (s) => count(s)); // lint fires here

...apply suggestion...

final map = Map<String, int>.fromIterable(strings, value: count);

error: The function 'count' has type '(String) → int' that isn't of expected type '(dynamic) → int'. This means its parameter or return type does not match what is expected.