Removed unused method, added @SInCE

Author: harawata

src/main/java/org/apache/ibatis/builder/annotation/ProviderSqlSource.java

@@ -23,7 +23,6 @@
 import org.apache.ibatis.builder.BuilderException;
 import org.apache.ibatis.mapping.BoundSql;
 import org.apache.ibatis.mapping.SqlSource;
-import org.apache.ibatis.parsing.PropertyParser;
 import org.apache.ibatis.reflection.ParamNameResolver;
 import org.apache.ibatis.scripting.LanguageDriver;
 import org.apache.ibatis.session.Configuration;
@@ -169,8 +168,4 @@ private String invokeProviderMethod(Object... args) throws Exception {
     return sql != null ? sql.toString() : null;
   }
 
-  private String replacePlaceholder(String sql) {
-    return PropertyParser.parse(sql, configuration.getVariables());
-  }
-
 }

src/main/java/org/apache/ibatis/session/Configuration.java

@@ -536,6 +536,9 @@ public LanguageDriver getDefaultScriptingLanguageInstance() {
     return languageRegistry.getDefaultDriver();
   }
 
+  /**
+   * @since 3.5.1
+   */
   public LanguageDriver getLanguageDriver(Class<? extends LanguageDriver> langClass) {
     if (langClass == null) {
       return languageRegistry.getDefaultDriver();