add hasIconData method

lib/ant_design.dart

@@ -3,6 +3,8 @@ class AntDesign {
   static getIconData(iconName){
     return FlutterIconData.antDesign(_antDesign[iconName]);
   }
+
+  static hasIconData(iconName)=>_antDesign.containsKey(iconName);
 }
 
 

lib/entypo.dart

@@ -4,6 +4,8 @@ class Entypo {
   static getIconData(String iconName){
     return FlutterIconData.entypo(_entypo[iconName]);
   }
+
+  static hasIconData(iconName)=>_entypo.containsKey(iconName);
 }
 const Map<String,int> _entypo ={
   "500px": 61696,

lib/evil_icons.dart

@@ -4,6 +4,8 @@ class EvilIcons {
   static getIconData(String iconName){
     return FlutterIconData.evilIcons(_evilIcons[iconName]);
   }
+
+  static hasIconData(iconName)=>_evilIcons.containsKey(iconName);
 }
 const Map<String, int> _evilIcons = {
   "archive": 61696,

lib/feather.dart

@@ -4,6 +4,8 @@ class Feather {
   static getIconData(String iconName){
     return FlutterIconData.feather(_feather[iconName]);
   }
+
+  static hasIconData(iconName)=>_feather.containsKey(iconName);
 }
 const Map<String,int> _feather ={
   "activity": 59648,

lib/font_awesome.dart

@@ -4,6 +4,8 @@ class FontAwesome {
   static getIconData(iconName){
     return FlutterIconData.fontAwesome(_fontAwesome[iconName]);
   }
+
+  static hasIconData(iconName)=>_fontAwesome.containsKey(iconName);
 }
 const Map<String ,int> _fontAwesome = {
   "glass": 61440,

lib/foundation.dart

@@ -4,6 +4,8 @@ class Foundation {
   static getIconData(String iconName){
     return FlutterIconData.foundation(_foundation[iconName]);
   }
+
+  static hasIconData(iconName)=>_foundation.containsKey(iconName);
 }
 const Map<String,int> _foundation = {
   "address-book": 61696,

lib/ionicons.dart

@@ -1,12 +1,15 @@
 import 'flutter_icon_data.dart';
+import 'package:flutter/material.dart';
 class Ionicons{
 
   static getIconData(String iconName) {
     return FlutterIconData.ionicons(_ionicons[iconName]);
   }
+
+  static hasIconData(iconName)=>_ionicons.containsKey(iconName);
 }
 
-final Map<String, int> _ionicons = const {
+const Map<String, int> _ionicons = const {
   "ios-add": 61698,
   "ios-add-circle": 61697,
   "ios-add-circle-outline": 61696,

lib/material_community_icons.dart

@@ -4,6 +4,8 @@ class MaterialCommunityIcons {
   static getIconData(String iconName){
     return FlutterIconData.materialCommunityIcons(_materialCommunityIcons[iconName]);
   }
+
+  static hasIconData(iconName)=>_materialCommunityIcons.containsKey(iconName);
 }
 
 const Map<String,int> _materialCommunityIcons = {

lib/material_icons.dart

@@ -3,6 +3,8 @@ class MaterialIcons {
   static getIconData(String iconName){
     return FlutterIconData.materialIcons(_materialIcons[iconName]);
   }
+  static hasIconData(iconName)=>_materialIcons.containsKey(iconName);
+
 }
 const Map<String,int> _materialIcons = {
   "3d-rotation": 59469,

lib/octicons.dart

@@ -4,6 +4,8 @@ class Octicons {
   static getIconData(String iconName){
     return FlutterIconData.octicons(_octicons[iconName]);
   }
+
+  static hasIconData(iconName)=>_octicons.containsKey(iconName);
 }
 const Map<String,int> _octicons ={
   "alert": 61696,

lib/simple_line_icons.dart

@@ -4,6 +4,8 @@ class SimpleLineIcons {
   static getIconData(String iconName){
     return FlutterIconData.simpleLineIcons(_simpleLineIcons[iconName]);
   }
+
+  static hasIconData(iconName)=>_simpleLineIcons.containsKey(iconName);
 }
 const Map<String,int> _simpleLineIcons = {
   "user": 57349,

lib/zocial.dart

@@ -3,6 +3,8 @@ class Zocial {
   static getIconData(String iconName){
     return FlutterIconData.zocial(_zocial[iconName]);
   }
+
+  static hasIconData(iconName)=>_zocial.containsKey(iconName);
 }
 const Map<String,int> _zocial = {
   "acrobat": 61696,