Added support for the bucket aggregation. (#797)

Signed-off-by: dblock <dblock@amazon.com>
Co-authored-by: mckirk <mckirk@posteo.de>

CHANGELOG.md

@@ -3,6 +3,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ## [Unreleased]
 ### Added
+- Added support for the `multi_terms` bucket aggregation ([#797](https://github.com/opensearch-project/opensearch-py/pull/797))
 ### Changed
 - Removed deprecated `numpy.float_` and update NumPy/Pandas imports ([#762](https://github.com/opensearch-project/opensearch-py/pull/762))
 - Removed workaround for [aiohttp#1769](https://github.com/aio-libs/aiohttp/issues/1769) ([#794](https://github.com/opensearch-project/opensearch-py/pull/794))

opensearchpy/helpers/aggs.py

@@ -308,6 +308,10 @@ class VariableWidthHistogram(Bucket):
         return FieldBucketData(self, search, data)
 
 
+class MultiTerms(Bucket):
+    name = "multi_terms"
+
+
 # metric aggregations
 class TopHits(Agg):
     name = "top_hits"

test_opensearchpy/test_helpers/test_aggs.py

@@ -309,6 +309,18 @@ def test_variable_width_histogram_aggregation() -> None:
     assert {"variable_width_histogram": {"buckets": 2, "field": "price"}} == a.to_dict()
 
 
+def test_multi_terms_aggregation() -> None:
+    a = aggs.MultiTerms(terms=[{"field": "tags"}, {"field": "author.row"}])
+    assert {
+        "multi_terms": {
+            "terms": [
+                {"field": "tags"},
+                {"field": "author.row"},
+            ]
+        }
+    } == a.to_dict()
+
+
 def test_median_absolute_deviation_aggregation() -> None:
     a = aggs.MedianAbsoluteDeviation(field="rating")