Don't emit Ruby warnings when requiring opensearch-dsl

CHANGELOG.md

@@ -8,6 +8,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Deprecated
 ### Removed
 ### Fixed
+- Don't emit Ruby warnings when requiring `opensearch-dsl` ([#231](https://github.com/opensearch-project/opensearch-ruby/issues/231))
 ### Security
 
 ## [3.2.0]

lib/opensearch/dsl/search/options.rb

@@ -55,10 +55,10 @@ def initialize(*_args)
           define_method name do |*args|
             @hash[name] = args.pop
           end
+        end
 
-          define_method name.to_s.gsub(/^_(.*)/, '\1') do |*args|
-            @hash[name] = args.pop
-          end
+        def source(*args)
+          @hash[:_source] = args.pop
         end
 
         # Returns true when there are no search options defined

lib/opensearch/dsl/search/queries/match.rb

@@ -59,7 +59,6 @@ class Match
           option_method :lenient
           option_method :zero_terms_query
           option_method :cutoff_frequency
-          option_method :max_expansions
         end
       end
     end