STY: update some drawing line comments

pydm/widgets/drawing.py

@@ -455,7 +455,7 @@ def alarm_severity_changed(self, new_alarm_severity):
 
 class PyDMDrawingLineBase(PyDMDrawing, new_properties=_penRuleProperties):
     """
-    A base class for single poly line widgets.
+    A base class for single and poly line widgets.
     This class inherits from PyDMDrawing.
 
     Parameters
@@ -468,20 +468,18 @@ class PyDMDrawingLineBase(PyDMDrawing, new_properties=_penRuleProperties):
 
     def __init__(self, parent=None, init_channel=None):
         super(PyDMDrawingLineBase, self).__init__(parent, init_channel)
-
         self.penStyle = Qt.SolidLine
         self.penWidth = 1
-
+        self._arrow_size = 6 # 6 is arbitrary size that looked good for default, not in any specific 'units'
         self._arrow_end_point_selection = False
         self._arrow_start_point_selection = False
         self._arrow_mid_point_selection = False
         self._arrow_mid_point_flipped = False
-        self._arrow_size = 6
 
     @Property(int)
     def arrowSize(self):
         """
-        If True, an arrow will be drawn at the end of the line.
+        Size to render line arrows.
 
         Returns
         -------