# Method Geography.GeoIP.IPv4()->create()

Method create

  `Geography.GeoIP.IPv4 Geography.GeoIP.IPv4(string file_name, function(string, ADT.CritBit.IPv4Tree:void) fun)`
  `Geography.GeoIP.IPv4 Geography.GeoIP.IPv4(ADT.CritBit.IPv4Tree tree)`

Description

  Objects of this class can either be created from a file `file_name` with an optional parsing function `fun`. When `fun` is omitted, it defaults to Geography.GeoIP.parse_maxmind. `fun` will be called for each line in `file_name` and the critbit tree to add the entry to.

  Alternatively, an instance of ADT.CritBit.IPv4Tree can be passed. `tree` is expected to map the first address of each range to its geographical location.