class SyntaxTree::Parser

def on_var_alias(left, right)

on_var_alias: (GVar left, (Backref | GVar) right) -> AliasNode
:call-seq: 
def on_var_alias(left, right)
  keyword = consume_keyword(:alias)
  AliasNode.new(
    left: left,
    right: right,
    location: keyword.location.to(right.location)
  )
end