       1mkeylget 4m22mlistvar24m ?4mkey24m? ?4mretvar24m | {}?
              Return  the value associated with 4mkey24m from the keyed list in the
              variable 4mlistvar24m.  If 4mretvar24m is not specified,  then  the  value
              will be returned as the result of the command.  In this case, if
              4mkey24m is not found in the list, an error will result.

              If 4mretvar24m is specified and 4mkey24m is in the list, then the value is
              returned in the variable 4mretvar24m and the command returns 1m1 22mif the
              key was present within the list.  If 4mkey24m isn't in the list,  the
              command will return 1m022m, and 4mretvar24m will be left unchanged.  If 1m{}0m
              is specified for 4mretvar24m, the value is not returned, allowing the
              Tcl  programmer to determine if a key is present in a keyed list
              without setting a variable as a side-effect.

              If 4mkey24m is omitted, then a list of all the keys in the keyed list
              is returned.
