Remove useless type specifications

@@ -73,7 +73,7 @@ class PdfCatalog extends PdfObject {
     params['/PageMode'] = PdfName(_PdfPageModes[pageMode.index]);
 
     if (pdfDocument.sign != null) {
-      params['/Perms'] = PdfDict(<String, PdfDataType>{
+      params['/Perms'] = PdfDict({
         '/DocMDP': pdfDocument.sign!.ref(),
       });
     }
@@ -88,7 +88,7 @@ class PdfCatalog extends PdfObject {
     }
 
     if (widgets.isNotEmpty) {
-      params['/AcroForm'] = PdfDict(<String, PdfDataType>{
+      params['/AcroForm'] = PdfDict({
         '/SigFlags': PdfNum(pdfDocument.sign?.flagsValue ?? 0),
         '/Fields': PdfArray.fromObjects(widgets),
       });

@@ -526,7 +526,7 @@ class PdfDict<T extends PdfDataType> extends PdfDataType {
     );
   }
 
-  final Map<String, T> values = <String, T>{};
+  final values = <String, T>{};
 
   bool get isNotEmpty => values.isNotEmpty;
 

@@ -127,7 +127,7 @@ mixin PdfGraphicStream on PdfObject {
 
     if (pdfDocument.hasGraphicStates) {
       // Declare Transparency Group settings
-      params['/Group'] = PdfDict(<String, PdfDataType>{
+      params['/Group'] = PdfDict({
         '/Type': const PdfName('/Group'),
         '/S': const PdfName('/Transparency'),
         '/CS': const PdfName('/DeviceRGB'),

@@ -36,8 +36,8 @@ class PdfNames extends PdfObject {
   }) {
     assert(page.pdfDocument == pdfDocument);
 
-    _dests[name] = PdfDict(<String, PdfDataType>{
-      '/D': PdfArray(<PdfDataType>[
+    _dests[name] = PdfDict({
+      '/D': PdfArray([
         page.ref(),
         const PdfName('/XYZ'),
         if (posX == null) const PdfNull() else PdfNum(posX),
@@ -63,7 +63,7 @@ class PdfNames extends PdfObject {
     final dict = PdfDict();
     if (dests.values.isNotEmpty) {
       dict['/Names'] = dests;
-      dict['/Limits'] = PdfArray(<PdfDataType>[
+      dict['/Limits'] = PdfArray([
         PdfSecString.fromString(this, keys.first),
         PdfSecString.fromString(this, keys.last),
       ]);

@@ -112,7 +112,7 @@ class PdfOutput {
       params['/Root'] = rootID!.ref();
       final id =
           PdfString(rootID!.pdfDocument.documentID, PdfStringFormat.binary);
-      params['/ID'] = PdfArray(<PdfDataType>[id, id]);
+      params['/ID'] = PdfArray([id, id]);
     } else {
       throw Exception('Root object is not present in document');
     }

@@ -111,19 +111,19 @@ class PdfTtfFont extends PdfFont {
     file.buf.putBytes(data);
     file.params['/Length1'] = PdfNum(data.length);
 
-    final descendantFont = PdfDict(<String, PdfDataType>{
+    final descendantFont = PdfDict({
       '/Type': const PdfName('/Font'),
       '/BaseFont': PdfName('/' + fontName),
       '/FontFile2': file.ref(),
       '/FontDescriptor': descriptor.ref(),
-      '/W': PdfArray(<PdfDataType>[
+      '/W': PdfArray([
         const PdfNum(0),
         widthsObject.ref(),
       ]),
       '/CIDToGIDMap': const PdfName('/Identity'),
       '/DW': const PdfNum(1000),
       '/Subtype': const PdfName('/CIDFontType2'),
-      '/CIDSystemInfo': PdfDict(<String, PdfDataType>{
+      '/CIDSystemInfo': PdfDict({
         '/Supplement': const PdfNum(0),
         '/Registry': PdfSecString.fromString(this, 'Adobe'),
         '/Ordering': PdfSecString.fromString(this, 'Identity-H'),
@@ -132,7 +132,7 @@ class PdfTtfFont extends PdfFont {
 
     params['/BaseFont'] = PdfName('/' + fontName);
     params['/Encoding'] = const PdfName('/Identity-H');
-    params['/DescendantFonts'] = PdfArray(<PdfDataType>[descendantFont]);
+    params['/DescendantFonts'] = PdfArray([descendantFont]);
     params['/ToUnicode'] = unicodeCMap.ref();
 
     charMin = 0;

@@ -76,11 +76,11 @@ void main() {
   test('PdfDataTypes Array', () {
     expect(PdfArray().toString(), '[]');
     expect(
-      PdfArray(<PdfDataType>[const PdfNum(1), const PdfNum(2)]).toString(),
+      PdfArray([const PdfNum(1), const PdfNum(2)]).toString(),
       '[1 2]',
     );
     expect(
-      PdfArray(<PdfDataType>[
+      PdfArray([
         const PdfName('/Name'),
         const PdfName('/Other'),
         const PdfBool(false),
@@ -98,15 +98,15 @@ void main() {
     expect(PdfDict().toString(), '<<>>');
 
     expect(
-      PdfDict(<String, PdfDataType>{
+      PdfDict({
         '/Name': const PdfName('/Value'),
         '/Bool': const PdfBool(true),
         '/Num': const PdfNum(42),
         '/String': PdfString.fromString('hello'),
         '/Null': const PdfNull(),
         '/Indirect': const PdfIndirect(55, 0),
-        '/Array': PdfArray(<PdfDataType>[]),
-        '/Dict': PdfDict(<String, PdfDataType>{}),
+        '/Array': PdfArray<PdfDataType>([]),
+        '/Dict': PdfDict<PdfDataType>({}),
       }).toString(),
       '<</Name/Value/Bool true/Num 42/String(hello)/Null null/Indirect 55 0 R/Array[]/Dict<<>>>>',
     );