Javadoc
For job execution path to files and file masks should be provided.
These values can be obtained in two ways:
1. As an argument of a current job entry
2. As a table, that comes as a result of execution previous job/transformation.
As the logic of processing this data is the same for both of this cases, we first
populate this data (in this method) and then process it.
We are using guava multimap here, because if allows key duplication and there could be a
situation where two paths to one folder with different wildcards are provided.