I'm trying to add to the TLF Table some missing parts. TLF Header is what I
actually need. I have first questions which may leads me how to move
1) In order to create header we need to set headerRowCount and TableElement
place for us TableCellElement in headerRows array 
2) Next step is put that elements in place. There is BaseCompose class and
composeTableElement method 
Mentioned method place table cells into TextFlowTableBlock .
My first question is - Should I create additional TextFlowTableBlock 
for the header and place there all the stuff
from headerRows array?
OR Should it be in the same TextFlowTableBlock ?