(PECL runkit >= 0.7.0)
runkit_import — Process a PHP file importing function and class definitions, overwriting where appropriate
$filename
   [, int $flags = RUNKIT_IMPORT_CLASS_METHODS
  ] )
   Similar to include however any code residing outside
   of a function or class is simply ignored.
   Additionally, depending on the value of flags,
   any functions or classes which already exist in the currently running environment
   will be automatically overwritten by their new definitions.
  
filenameFilename to import function and class definitions from
flags
       Bitwise OR of the RUNKIT_IMPORT_* family of constants.
      
   Returns TRUE on success or FALSE on failure.