new

# File activerecord/lib/active_record/associations/join_dependency.rb, line 8
        def initialize(tables)
          @tables = tables
          @alias_cache = tables.each_with_object({}) { |table,h|
            h[table.node] = table.columns.each_with_object({}) { |column,i|
              i[column.name] = column.alias
            }
          }
          @name_and_alias_cache = tables.each_with_object({}) { |table,h|
            h[table.node] = table.columns.map { |column|
              [column.name, column.alias]
            }
          }
        end