class Prism::CallOrWriteNode

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?(CallOrWriteNode) &&
    (flags === other.flags) &&
    (receiver === other.receiver) &&
    (call_operator_loc.nil? == other.call_operator_loc.nil?) &&
    (message_loc.nil? == other.message_loc.nil?) &&
    (read_name === other.read_name) &&
    (write_name === other.write_name) &&
    (operator_loc.nil? == other.operator_loc.nil?) &&
    (value === other.value)
end