Add new APIs.

Author: teo-tsirpanis

sources/TileDB.CSharp/QueryField.cs

@@ -53,6 +53,21 @@ public DataType DataType
         }
     }
 
+    /// <summary>
+    /// Gets whether the <see cref="QueryField"/> is nullable.
+    /// </summary>
+    public bool IsNullable
+    {
+        get
+        {
+            using var ctxHandle = _ctx.Handle.Acquire();
+            using var handle = _handle.Acquire();
+            byte result;
+            _ctx.handle_error(Methods.tiledb_field_get_nullable(ctxHandle, handle, &result));
+            return result != 0;
+        }
+    }
+
     /// <summary>
     /// Gets the origin of the <see cref="QueryField"/>.
     /// </summary>

sources/TileDB.CSharp/Stats.cs

@@ -18,6 +18,20 @@ public static unsafe class Stats
     /// </summary>
     public static void Disable() => ErrorHandling.ThrowOnError(Methods.tiledb_stats_disable());
 
+    /// <summary>
+    /// Gets whether statistics are enabled.
+    /// </summary>
+    /// <seealso cref="Enable"/>
+    /// <seealso cref="Disable"/>
+    public static bool IsEnabled
+    {
+        get {
+            byte val;
+            ErrorHandling.ThrowOnError(Methods.tiledb_stats_is_enabled(&val));
+            return val != 0;
+        }
+    }
+
     /// <summary>
     /// Resets all previously gathered statistics.
     /// </summary>