anchor.diff:      bool showMetadata = true,
       bool showNames = true,
     }) {
  -    var buffer = StringBuffer();
  -    buffer.write(prefix);
  -    var paramModelType = param.modelType;
  +    final buffer = StringBuffer(prefix);
  +    final modelType = param.modelType;
   
       if (showMetadata && param.hasAnnotations) {
  -      for (var a in param.annotations) {
  -        buffer.write(annotation(a.linkedNameWithParameters));
  -        buffer.write(' ');
  +      for (final a in param.annotations) {
  +        buffer.write('${annotation(a.linkedNameWithParameters)} ');
         }
       }
       if (param.isRequiredNamed) {
  
positive.code:     if (param.isCovariant) {
        buffer.write('${covariant('covariant')} ');
      }
      if (paramModelType is Callable) {
        String returnTypeName;
        if (paramModelType.isTypedef) {
          returnTypeName = paramModelType.linkedName;
        } else {
          returnTypeName = paramModelType.returnType.linkedName;
        }
        buffer.write(typeName(returnTypeName));
        if (showNames) {
          buffer.write(' ${parameterName(param.name)}');
        } else {
          buffer.write(' ${parameterName(paramModelType.name)}');
        }
        if (!paramModelType.isTypedef && paramModelType is DefinedElementType) {
          buffer.write('(');
          buffer.write(renderLinkedParams(
            (paramModelType as DefinedElementType).modelElement.parameters,
            showMetadata: showMetadata,
            showNames: showNames,
          ));
          buffer.write(')');
          buffer.write(paramModelType.nullabilitySuffix);
        }
        if (!paramModelType.isTypedef) {
          buffer.write('(');
          buffer.write(renderLinkedParams(
            paramModelType.parameters,
            showMetadata: showMetadata,
            showNames: showNames,
          ));
          buffer.write(')');
          buffer.write(paramModelType.nullabilitySuffix);
        }
      } else {
        var linkedTypeName = paramModelType.linkedName;
        if (linkedTypeName.isNotEmpty) {
          buffer.write(typeName(linkedTypeName));
          if (showNames && param.name.isNotEmpty) {
  
negative.code:       } else {
          suffix += ', ';
        }
        final renderedParameter = _renderParameter(
          p,
          prefix: prefix,
          suffix: suffix,
  