Speed up creation of data series

I set the size of the dataseries so that we do not need to grow the collection as we add elements (it can double the speed on creation)

Author: jecisc

src/DataFrame/DataSeries.class.st

@@ -21,6 +21,16 @@ DataSeries class >> newFrom: aCollection [
 		ifFalse: [ aCollection withIndexCollect: [ :each :i | i -> each ] ])
 ]
 
+{ #category : #'instance creation' }
+DataSeries class >> newFromKeys: keys andValues: values [
+
+	| dict |
+	self flag: #pharo12. "This is a copy of the superclass with a speed up. I'll propose this speedup in Pharo 12 so when Pharo 12 will be the minimal suuported version then we can drop this method."
+	dict := self new: keys size.
+	keys with: values do: [ :k :v | dict at: k put: v ].
+	^ dict
+]
+
 { #category : #'instance creation' }
 DataSeries class >> withKeys: keys values: values [
 	^ self newFromKeys: keys andValues: values