class ActiveModel::GlobalLocator

def locate(gid)

Takes either a GlobalID or a string that can be turned into a GlobalID 
def locate(gid)
  if gid.is_a? GlobalID
    gid.model_class.find(gid.model_id)
  elsif properly_formatted_gid?(gid)
    locate GlobalID.new(gid)
  end
end

def locate_signed(sgid)

Takes either a SignedGlobalID or a string that can be turned into a SignedGlobalID 
def locate_signed(sgid)
  if sgid.is_a? SignedGlobalID
    sgid.model_class.find(sgid.model_id)
  else
    locate_signed SignedGlobalID.new(sgid)
  end
end

def properly_formatted_gid?(gid) 

def properly_formatted_gid?(gid)
  gid =~ /GlobalID-([^-]+)-(.+)/
end