How to use the laspy.header.LaspyHeaderException function in laspy

def set_pointrecordscount(self, value):
        if not self.file_mode in ("w", "w+","rw"):
            raise LaspyHeaderException("File must be open in a write mode to modify point_records_count.")
        self.writer.set_header_property("point_records_count", value)
        
        '''Sets the number of point records expected in the file.

        .. note::
            Don't use this unless you have a damn good reason to. As you write
            points to a file, laspy is going to keep this up-to-date for you
            and write it back into the header of the file once the file is
            closed after writing data.
        '''
        return
    set_count = set_pointrecordscount

def assertWriteMode(self):
        '''Assert that header has permission to write data to file.'''
        if self.file_mode == "r":
            raise LaspyHeaderException("Header instance is not in write mode.")

def set_dataformatid(self, value):
        '''Set the data format ID. This is only available for files in write mode which have not yet been given points.'''
        if value not in range(6):
            raise LaspyHeaderException("Format ID must be 3, 2, 1, or 0")
        if not self.file_mode in ("w", "w+"):
            raise LaspyHeaderException("Point Format ID can only be set for " + 
                                        "files in write or append mode.")
        if self.writer.get_pointrecordscount() > 0:
            raise LaspyHeaderException("Modification of the format of existing " + 
                                        "points is not currently supported. Make " + 
                                        "your modifications in numpy and create " + 
                                        "a new file.")
        self.writer.set_header_property("data_format_id", value)
        return 
    '''The data format ID for the file, determines what point fields are present.'''

def set_dataformatid(self, value):
        '''Set the data format ID. This is only available for files in write mode which have not yet been given points.'''
        if value not in range(6):
            raise LaspyHeaderException("Format ID must be 3, 2, 1, or 0")
        if not self.file_mode in ("w", "w+"):
            raise LaspyHeaderException("Point Format ID can only be set for " + 
                                        "files in write or append mode.")
        if self.writer.get_pointrecordscount() > 0:
            raise LaspyHeaderException("Modification of the format of existing " + 
                                        "points is not currently supported. Make " + 
                                        "your modifications in numpy and create " + 
                                        "a new file.")
        self.writer.set_header_property("data_format_id", value)
        return 
    '''The data format ID for the file, determines what point fields are present.'''