chore: make method internal; update public API

Author: MaggieKimani1

src/Microsoft.OpenApi/Extensions/OpenApiTypeMapper.cs

@@ -54,7 +54,7 @@ public static string[] ToIdentifier(this JsonSchemaType schemaType)
         /// </summary>
         /// <param name="schemaType"></param>
         /// <returns></returns>
-        public static string FirstIdentifier(this JsonSchemaType schemaType)
+        internal static string FirstIdentifier(this JsonSchemaType schemaType)
         {
             var identifier = schemaType.ToIdentifier();
             return identifier[0];

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -193,7 +193,7 @@ namespace Microsoft.OpenApi.Extensions
         public static string[] ToIdentifier(this Microsoft.OpenApi.Models.JsonSchemaType schemaType) { }
         public static string[]? ToIdentifier(this Microsoft.OpenApi.Models.JsonSchemaType? schemaType) { }
         public static Microsoft.OpenApi.Models.JsonSchemaType ToJsonSchemaType(this string identifier) { }
-        public static Microsoft.OpenApi.Models.JsonSchemaType ToJsonSchemaType(this string[] identifier) { }
+        public static Microsoft.OpenApi.Models.JsonSchemaType? ToJsonSchemaType(this string[] identifier) { }
     }
 }
 namespace Microsoft.OpenApi.Interfaces