@Override
                public Set<Entry<String, MemberShape>> entrySet() {
                    Set<Entry<String, MemberShape>> result = entries;
                    if (result == null) {
                        result = SetUtils.of(Pair.of("key", key), Pair.of("value", value));
                        entries = result;
                    }
                    return result;
                }
Get the key member shape of the map.

@return Returns the key member shape.
smithy-model/src/main/java/software/amazon/smithy/model/shapes/MapShape.java