Flatten all fields of the document or of a range of pages. Flattening a field of a PDF document makes its appearance part of the page and removes the selected widget or all widgets; the field will be removed when all its widgets have been flattened. This function selects all widgets on the specified pages. Flattening unsigned signature fields does not work correctly. Flattening fields breaks existing signatures. If you are flattening fields only for printing with PDF components that don't support annotations, make a copy of the document, pass to setShootInFoot(), flatten the fields, print the document, and throw it away.

public void flattenFields(
	int firstPage,
	int lastPage,
	FlattenFieldsFlag flags
)