Added least documents

Author: nobu

lib/ruby2_keywords.rb

@@ -1,5 +1,9 @@
 class Module
   unless private_method_defined?(:ruby2_keywords, true)
+    # call-seq:
+    #    ruby2_keywords(method_name, ...)
+    #
+    # Does nothing.
     private
     def ruby2_keywords(name, *)
       # nil
@@ -9,13 +13,21 @@ def ruby2_keywords(name, *)
 
 main = TOPLEVEL_BINDING.receiver
 unless main.respond_to?(:ruby2_keywords, true)
+  # call-seq:
+  #    ruby2_keywords(method_name, ...)
+  #
+  # Does nothing.
   def main.ruby2_keywords(name, *)
     # nil
   end
 end
 
 class Proc
   unless method_defined?(:ruby2_keywords)
+    # call-seq:
+    #    proc.ruby2_keywords -> proc
+    #
+    # Does nothing and just returns the receiver.
     def ruby2_keywords
       self
     end
@@ -24,12 +36,20 @@ def ruby2_keywords
 
 class << Hash
   unless method_defined?(:ruby2_keywords_hash?)
+    # call-seq:
+    #    Hash.ruby2_keywords_hash?(hash) -> false
+    #
+    # Returns false.
     def ruby2_keywords_hash?(hash)
       false
     end
   end
 
   unless method_defined?(:ruby2_keywords_hash)
+    # call-seq:
+    #    Hash.ruby2_keywords_hash(hash) -> new_hash
+    #
+    # Duplicates a given hash and returns the new hash.
     def ruby2_keywords_hash(hash)
       hash.dup
     end