Avoid creating intermediate map when creating immutable capabilities

Author: shs96c

java/client/src/org/openqa/selenium/ImmutableCapabilities.java

@@ -68,10 +68,12 @@ public ImmutableCapabilities(
   }
 
   public ImmutableCapabilities(Capabilities other) {
-    this(other.asMap());
+    Require.nonNull("Capabilities", other);
+    other.getCapabilityNames().forEach(name -> delegate.setCapability(name, other.getCapability(name)));
   }
 
   public ImmutableCapabilities(Map<?, ?> capabilities) {
+    Require.nonNull("Capabilities", capabilities);
     capabilities.forEach((key, value) -> {
       Require.argument("Key", key).instanceOf(String.class);
       delegate.setCapability(String.valueOf(key), value);
@@ -118,4 +120,4 @@ public static ImmutableCapabilities copyOf(Capabilities capabilities) {
 
     return new ImmutableCapabilities(capabilities);
   }
-}
+}