improve exception message

Author: jinseopkim0

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientV2.java

@@ -324,7 +324,8 @@ private UnaryCallable<ConsistencyRequest, Void> getAwaitConsistencyCallable() {
     }
     throw new IllegalStateException(
         "AwaitConsistencyCallable not initialized. BigtableTableAdminClientV2 must be "
-            + "initialized via settings to use this functionality.");
+            + "initialized via BigtableTableAdminClientV2.create(BaseBigtableTableAdminSettings) "
+            + "to use this functionality.");
   }
 
   private OperationCallable<Void, Empty, OptimizeRestoredTableMetadata>
@@ -334,6 +335,7 @@ private UnaryCallable<ConsistencyRequest, Void> getAwaitConsistencyCallable() {
     }
     throw new IllegalStateException(
         "OptimizeRestoredTableCallable not initialized. BigtableTableAdminClientV2 must be "
-            + "initialized via settings to use this functionality.");
+            + "initialized via BigtableTableAdminClientV2.create(BaseBigtableTableAdminSettings) "
+            + "to use this functionality.");
   }
 }

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/BigtableTableAdminClientV2Test.java

@@ -152,4 +152,34 @@ public void testCreateClientWithSettings() throws Exception {
       assertThat(settingsClient.getStub()).isNotInstanceOf(EnhancedBigtableTableAdminStub.class);
     }
   }
+
+  @Test
+  public void testAwaitConsistency_ThrowsWhenNotInitialized() {
+    BigtableTableAdminClientV2 uninitializedClient = BigtableTableAdminClientV2.create(mockStub);
+
+    try {
+      uninitializedClient.waitForConsistency(TABLE_NAME, "token");
+      org.junit.Assert.fail("Expected IllegalStateException");
+    } catch (IllegalStateException e) {
+      assertThat(e.getMessage())
+          .contains("BigtableTableAdminClientV2.create(BaseBigtableTableAdminSettings)");
+    }
+  }
+
+  @Test
+  public void testOptimizeRestoredTable_ThrowsWhenNotInitialized() {
+    BigtableTableAdminClientV2 uninitializedClient = BigtableTableAdminClientV2.create(mockStub);
+
+    OptimizeRestoredTableOperationToken mockToken =
+        Mockito.mock(OptimizeRestoredTableOperationToken.class);
+    Mockito.when(mockToken.getOperationName()).thenReturn("op-name");
+
+    try {
+      uninitializedClient.awaitOptimizeRestoredTableAsync(mockToken);
+      org.junit.Assert.fail("Expected IllegalStateException");
+    } catch (IllegalStateException e) {
+      assertThat(e.getMessage())
+          .contains("BigtableTableAdminClientV2.create(BaseBigtableTableAdminSettings)");
+    }
+  }
 }