# File lib/mongo/client.rb, line 558
    def list_databases(filter = {}, name_only = false, opts = {})
      cmd = { listDatabases: 1 }
      cmd[:nameOnly] = !!name_only
      cmd[:filter] = filter unless filter.empty?
      use(Database::ADMIN).command(cmd, opts).first[Database::DATABASES]
    end