class ActionView::UnboundTemplate

def bind_locals(locals)
  if template = @templates[locals]
    template
  else
    @write_lock.synchronize do
      normalized_locals = normalize_locals(locals)
      # We need ||=, both to dedup on the normalized locals and to check
      # while holding the lock.
      @templates[normalized_locals] ||= build_template(normalized_locals)
      # This may have already been assigned, but we've already de-dup'd so
      # reassignment is fine.
      @templates[locals.dup] = @templates[normalized_locals]
    end
  end
end