.addParagraph("2.2This is a test paragraph apply with Heading 2 style!");
p22.applyHeading(true, 2);
Paragraph p221 = doc
.addParagraph("2.2.1This is a test paragraph apply with Heading 3 style!");
p221.applyHeading(true, 3);
Paragraph p222 = doc
.addParagraph("2.2.2This is a test paragraph apply with Heading 3 style!");
p222.applyHeading(true, 3);
Paragraph p23 = doc
.addParagraph("2.3This is a test paragraph apply with Heading 2 style!");
p23.applyHeading(true, 2);