class Prism::ParenthesesNode

def ===(other)

comparing the value of locations. Locations are checked only for presence.
Implements case-equality for the node. This is effectively == but without 
def ===(other)
  other.is_a?(ParenthesesNode) &&
    (body === other.body) &&
    (opening_loc.nil? == other.opening_loc.nil?) &&
    (closing_loc.nil? == other.closing_loc.nil?)
end