Merge pull request #15 from spi-x-i/fixing-documentation

Fixing explanation about model loading phase

README.md

@@ -125,7 +125,7 @@ object FlinkJpmmlExample {
 Some useful insights from the code:
 - in order to load the PMML model, you need to specify only the PMML source path
 - `ModelReader` is a lazy reader and it provides the right reading abstraction to TaskManagers
-- The resulting `PMMLModel` will be **loaded once** for each TaskManager running on your architecture at 
+- The resulting `PMMLModel` will be **loaded by once** factory for each TaskManager running on your architecture at 
 _construction time_
 - the `PmmlModel.predict` method expects Flink Vectors as input event and, if you want to manage NaNs, an optional 
 replace value;
@@ -155,9 +155,9 @@ the library will take care how to load the model in full compliance of the under
 (e.g. HDFS, Alluxio)
 - `ModelReader` is the object implementing the previous behavior; it will provide the loading methods but will read it 
 _lazily_, _i.e._ only when the transformation will be applied
-- The `PMMLModel` will be loaded once for each TaskManager running on your architecture; that means if you have an
-active TaskManager _A_ made up of 4 TaskSlots, your TM will load **one and only one** shared copy of the model; this is 
-crucial in order to let the system scale (still simple PMML models can grow to several hundreds of MegaBytes 
+- The `PMMLModel` will be loaded by a singleton model factory for each TaskManager running on your architecture; that means if you have an
+active TaskManager _A_ made up of 4 TaskSlots, your TM will load the model from a single loader entity; this is 
+crucial in order to let the system scale in thread-safety (still simple PMML models can grow to several hundreds of MegaBytes 
 proportionally to the model size, meaning a big load in memory terms)
 - the `PmmlModel.predict` method expects Flink Vectors as input events; this choice let us to leverage the underlying 
 Breeze implementation and **no reflection** will be applied at all; moreover, the user don't have to specify any