2021.2.21

Has backward incompatible changes:
Drop method "transform"
Drop param "receive_all_data"

Other:
translated into english
add iteration method "parts"
add iteration method "lines"
add iteration method "values"
add iteration method "iter_lines"
add iteration method "iter_values"
add attribut "columns"
add attribut "data"
add attribut "response"
add method "to_lines"
add method "to_values"
add method "to_columns"
and other