try to adjust test

psutil/_psosx.py

@@ -110,16 +110,12 @@
 
 def virtual_memory():
     """System virtual memory as a namedtuple."""
-    total, active, inactive, wired, free, speculative = cext.virtual_mem()
+    total, active, inactive, wired, free, _speculative = cext.virtual_mem()
     # This is how Zabbix calculate avail and used mem:
-    # https://github.com/zabbix/zabbix/blob/trunk/src/libs/zbxsysinfo/
-    #     osx/memory.c
+    # https://github.com/zabbix/zabbix/blob/master/src/libs/zbxsysinfo/osx/memory.c
     # Also see: https://github.com/giampaolo/psutil/issues/1277
     avail = inactive + free
     used = active + wired
-    # This is NOT how Zabbix calculates free mem but it matches "free"
-    # cmdline utility.
-    free -= speculative
     percent = usage_percent((total - avail), total, round_=1)
     return svmem(total, avail, percent, used, free, active, inactive, wired)