def _header(self, pam=False):
if pam or self.magicnum == b'<STR_LIT>':<EOL><INDENT>header = "<STR_LIT:\n>".join((<EOL>"<STR_LIT>",<EOL>"<STR_LIT>" % self.height,<EOL>"<STR_LIT>" % self.width,<EOL>"<STR_LIT>" % self.depth,<EOL>"<STR_LIT>" % self.maxval,<EOL>"<STR_LIT:\n>".join("<STR_LIT>" % unicode(i) for i in self.tupltypes),<EOL>"<STR_LIT>"))<EOL><DEDENT>elif self.maxval == <NUM_LIT:1>:<EOL><INDENT>header = "<STR_LIT>" % (self.width, self.height)<EOL><DEDENT>elif self.depth == <NUM_LIT:1>:<EOL><INDENT>header = "<STR_LIT>" % (self.width, self.height, self.maxval)<EOL><DEDENT>else:<EOL><INDENT>header = "<STR_LIT>" % (self.width, self.height, self.maxval)<EOL><DEDENT>if sys.version_info[<NUM_LIT:0>] > <NUM_LIT:2>:<EOL><INDENT>header = bytes(header, '<STR_LIT:ascii>')<EOL><DEDENT>return header<EOL>
Return file header as byte string.