src/DiffMatchPatch.php
public function diff_cleanupEfficiency(&$diffs)
    {
        $this->diff->setChanges($diffs);
        $this->diff->cleanupEfficiency();
        $diffs = $this->diff->getChanges();
    }
public function diff_cleanupEfficiency(&$diffs)
    {
        $this->diff->setChanges($diffs);
        $this->diff->cleanupEfficiency();
        $diffs = $this->diff->getChanges();
    }
Reduce the number of edits by eliminating operationally trivial equalities.
Modifies $diffs.

@param array $diffs Array of diff arrays.