original_string: public function getSourceByName($sourceName)
      {
          if (isset($this->sources[$sourceName])) {
              return $this->sources[$sourceName];
          }
          return null;
      }
code: public function getSourceByName($sourceName)
      {
          if (isset($this->sources[$sourceName])) {
              return $this->sources[$sourceName];
          }
          return null;
      }
code_tokens: public function getSourceByName ( $ sourceName ) { if ( isset ( $ this -> sources [ $ sourceName ] ) ) { return $ this -> sources [ $ sourceName ] ; } return null ; }
docstring: Returns the Source object for the given source name
  
  @param string $sourceName the source name
  
  @return null|SourceInterface
docstring_tokens: Returns the Source object for the given source name