- fixes a bug where a null collection for allowed hosts would fail client initialization

Author: baywet

src/main/java/com/microsoft/graph/core/authentication/AzureIdentityAccessTokenProvider.java

@@ -1,6 +1,7 @@
 package com.microsoft.graph.core.authentication;
 
 import java.util.HashSet;
+import java.util.Objects;
 
 import jakarta.annotation.Nonnull;
 import jakarta.annotation.Nullable;
@@ -22,7 +23,7 @@ public AzureIdentityAccessTokenProvider(@Nonnull TokenCredential tokenCredential
     public AzureIdentityAccessTokenProvider(@Nonnull final TokenCredential tokenCredential, @Nonnull final String[] allowedHosts,
             @Nullable final ObservabilityOptions observabilityOptions, @Nonnull final String... scopes) {
         super(tokenCredential, allowedHosts, observabilityOptions, scopes);
-        if (allowedHosts.length == 0) {
+        if (allowedHosts == null || allowedHosts.length == 0) {
             final HashSet<String> allowedHostsSet = new HashSet<String>();
             allowedHostsSet.add("graph.microsoft.com");
             allowedHostsSet.add("graph.microsoft.us");