import 'dart:io'; extension MapExtension on Map { bool hasKeyContentType() { return keys.any((k) => (k is String) ? k.toLowerCase() == HttpHeaders.contentTypeHeader : false); } String? getKeyContentType() { if (isEmpty) { return null; } bool present = hasKeyContentType(); if (present) { return keys.firstWhere((e) => (e is String) ? e.toLowerCase() == HttpHeaders.contentTypeHeader : false); } return null; } String? getValueContentType() { return this[getKeyContentType()]; } Map removeKeyContentType() { removeWhere( (key, value) => key.toLowerCase() == HttpHeaders.contentTypeHeader); return this; } }