Revert "wikipedia-kyoto-japanese-english: increase REXML entity expan…

…sion limit during XML parsing (#198) (#201)

This reverts commit a76b917.

REXML has fixed the bug where
`REXML::Security.entity_expansion_text_limit` incorrectly calculated
text size in both SAX and pull parsers. Therefore, we no longer need to
handle this issue within Red Datasets.

ref: https://github.com/ruby/rexml/releases/tag/v3.3.5

lib/datasets/wikipedia-kyoto-japanese-english.rb

@@ -89,9 +89,7 @@ def each(&block)
             next unless base_name.end_with?(".xml")
             listener = ArticleListener.new(block)
             parser = REXML::Parsers::StreamParser.new(entry.read, listener)
-            with_increased_entity_expansion_text_limit do
-              parser.parse
-            end
+            parser.parse
           when :lexicon
             next unless base_name == "kyoto_lexicon.csv"
             is_header = true
@@ -108,9 +106,6 @@ def each(&block)
     end
 
     private
-
-    ENTITY_EXPANSION_TEXT_LIMIT = 163_840
-
     def download_tar_gz
       base_name = "wiki_corpus_2.01.tar.gz"
       data_path = cache_dir_path + base_name
@@ -119,14 +114,6 @@ def download_tar_gz
       data_path
     end
 
-    def with_increased_entity_expansion_text_limit
-      default_limit = REXML::Security.entity_expansion_text_limit
-      REXML::Security.entity_expansion_text_limit = ENTITY_EXPANSION_TEXT_LIMIT
-      yield
-    ensure
-      REXML::Security.entity_expansion_text_limit = default_limit
-    end
-
     class ArticleListener
       include REXML::StreamListener