Prototype: Complex attributes (Option A)

api/all/src/main/java/io/opentelemetry/api/common/AttributeKey.java

@@ -70,4 +70,16 @@ static AttributeKey<List<Long>> longArrayKey(String key) {
   static AttributeKey<List<Double>> doubleArrayKey(String key) {
     return InternalAttributeKeyImpl.create(key, AttributeType.DOUBLE_ARRAY);
   }
+
+  static AttributeKey<byte[]> byteArrayKey(String key) {
+    return InternalAttributeKeyImpl.create(key, AttributeType.BYTE_ARRAY);
+  }
+
+  static AttributeKey<List<Value<?>>> valueArrayKey(String key) {
+    return InternalAttributeKeyImpl.create(key, AttributeType.VALUE_ARRAY);
+  }
+
+  static AttributeKey<Attributes> mapKey(String key) {
+    return InternalAttributeKeyImpl.create(key, AttributeType.MAP);
+  }
 }

api/all/src/main/java/io/opentelemetry/api/common/AttributeType.java

@@ -17,5 +17,8 @@ public enum AttributeType {
   STRING_ARRAY,
   BOOLEAN_ARRAY,
   LONG_ARRAY,
-  DOUBLE_ARRAY
+  DOUBLE_ARRAY,
+  BYTE_ARRAY,
+  VALUE_ARRAY,
+  MAP
 }

api/all/src/main/java/io/opentelemetry/api/common/Value.java

@@ -84,6 +84,10 @@ static Value<List<KeyValue>> of(Map<String, Value<?>> value) {
     return KeyValueList.createFromMap(value);
   }
 
+  static Value<List<KeyValue>> of(Attributes attributes) {
+    // TODO
+  }
+
   /** Returns the type of this {@link Value}. Useful for building switch statements. */
   ValueType getType();