restore order of null-handling section

Author: jbrockmendel

pandas/core/arrays/datetimelike.py

@@ -748,6 +748,23 @@ def map(self, mapper):
     # ------------------------------------------------------------------
     # Null Handling
 
+    def isna(self):
+        return self._isnan
+
+    @property  # NB: override with cache_readonly in immutable subclasses
+    def _isnan(self):
+        """
+        return if each value is nan
+        """
+        return (self.asi8 == iNaT)
+
+    @property  # NB: override with cache_readonly in immutable subclasses
+    def _hasnans(self):
+        """
+        return if I have any nans; enables various perf speedups
+        """
+        return bool(self._isnan.any())
+
     def _maybe_mask_results(self, result, fill_value=iNaT, convert=None):
         """
         Parameters
@@ -774,23 +791,6 @@ def _maybe_mask_results(self, result, fill_value=iNaT, convert=None):
             result[self._isnan] = fill_value
         return result
 
-    def isna(self):
-        return self._isnan
-
-    @property  # NB: override with cache_readonly in immutable subclasses
-    def _isnan(self):
-        """
-        return if each value is nan
-        """
-        return (self.asi8 == iNaT)
-
-    @property  # NB: override with cache_readonly in immutable subclasses
-    def _hasnans(self):
-        """
-        return if I have any nans; enables various perf speedups
-        """
-        return bool(self._isnan.any())
-
     def fillna(self, value=None, method=None, limit=None):
         # TODO(GH-20300): remove this
         # Just overriding to ensure that we avoid an astype(object).