class Prism::OptionalKeywordParameterNode

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?(OptionalKeywordParameterNode) &&
    (flags === other.flags) &&
    (name === other.name) &&
    (name_loc.nil? == other.name_loc.nil?) &&
    (value === other.value)
end