How to use the birdears.urwid.compat.B function in birdears

elif self.parsestate == 0 and char == B(']'):
            # start of OSC
            self.escbuf = bytes()
            self.parsestate = 2
            return
        elif self.parsestate == 2 and char == B("\x07"):
            # end of OSC
            self.parse_osc(self.escbuf.lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf[-1:] + char == B(ESC + '\\'):
            # end of OSC
            self.parse_osc(self.escbuf[:-1].lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf.startswith(B('P')) and \
             len(self.escbuf) == 8:
            # set palette (ESC]Pnrrggbb)
            pass
        elif self.parsestate == 2 and not self.escbuf and char == B('R'):
            # reset palette
            pass
        elif self.parsestate == 2:
            self.escbuf += char
            return
        elif self.parsestate == 0 and char == B('['):
            # start of CSI
            self.escbuf = bytes()
            self.parsestate = 1
            return
        elif self.parsestate == 0 and char in (B('%'), B('#'), B('('), B(')')):
            # non-CSI sequence
            self.escbuf = char
            self.parsestate = 3
            return
        elif self.parsestate == 3:

self.parsestate = 0
            elif char in B('0123456789;') or (not self.escbuf and char == B('?')):
                self.escbuf += char
                return
        elif self.parsestate == 0 and char == B(']'):
            # start of OSC
            self.escbuf = bytes()
            self.parsestate = 2
            return
        elif self.parsestate == 2 and char == B("\x07"):
            # end of OSC
            self.parse_osc(self.escbuf.lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf[-1:] + char == B(ESC + '\\'):
            # end of OSC
            self.parse_osc(self.escbuf[:-1].lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf.startswith(B('P')) and \
             len(self.escbuf) == 8:
            # set palette (ESC]Pnrrggbb)
            pass
        elif self.parsestate == 2 and not self.escbuf and char == B('R'):
            # reset palette
            pass
        elif self.parsestate == 2:
            self.escbuf += char
            return
        elif self.parsestate == 0 and char == B('['):
            # start of CSI
            self.escbuf = bytes()
            self.parsestate = 1
            return
        elif self.parsestate == 0 and char in (B('%'), B('#'), B('('), B(')')):
            # non-CSI sequence

"""
        Set G0 or G1 according to 'char' and modifier 'mod'.
        """
        if self.modes.main_charset != CHARSET_DEFAULT:
            return

        if mod == B('('):
            g = 0
        else:
            g = 1

        if char == B('0'):
            cset = 'vt100'
        elif char == B('U'):
            cset = 'ibmpc'
        elif char == B('K'):
            cset = 'user'
        else:
            cset = 'default'

        self.charset.define(g, cset)

def tab(self, tabstop=8):
        """
        Moves cursor to the next 'tabstop' filling everything in between
        with spaces.
        """
        x, y = self.term_cursor

        while x < self.width - 1:
            self.set_char(B(" "))
            x += 1

            if self.is_tabstop(x):
                break

        self.is_rotten_cursor = False
        self.set_term_cursor(x, y)

elif self.parsestate == 2:
            self.escbuf += char
            return
        elif self.parsestate == 0 and char == B('['):
            # start of CSI
            self.escbuf = bytes()
            self.parsestate = 1
            return
        elif self.parsestate == 0 and char in (B('%'), B('#'), B('('), B(')')):
            # non-CSI sequence
            self.escbuf = char
            self.parsestate = 3
            return
        elif self.parsestate == 3:
            self.parse_noncsi(char, self.escbuf)
        elif char in (B('c'), B('D'), B('E'), B('H'), B('M'), B('Z'), B('7'), B('8'), B('>'), B('=')):
            self.parse_noncsi(char)

        self.leave_escape()

def parse_escape(self, char):
        if self.parsestate == 1:
            # within CSI
            if char in CSI_COMMANDS.keys():
                self.parse_csi(char)
                self.parsestate = 0
            elif char in B('0123456789;') or (not self.escbuf and char == B('?')):
                self.escbuf += char
                return
        elif self.parsestate == 0 and char == B(']'):
            # start of OSC
            self.escbuf = bytes()
            self.parsestate = 2
            return
        elif self.parsestate == 2 and char == B("\x07"):
            # end of OSC
            self.parse_osc(self.escbuf.lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf[-1:] + char == B(ESC + '\\'):
            # end of OSC
            self.parse_osc(self.escbuf[:-1].lstrip(B('0')))
        elif self.parsestate == 2 and self.escbuf.startswith(B('P')) and \
             len(self.escbuf) == 8:
            # set palette (ESC]Pnrrggbb)

def parse_osc(self, buf):
        """
        Parse operating system command.
        """
        if buf.startswith(B(';')): # set window title and icon
            self.widget.set_title(buf[1:])
        elif buf.startswith(B('3;')): # set window title
            self.widget.set_title(buf[2:])

def parse_noncsi(self, char, mod=None):
        """
        Parse escape sequences which are not CSI.
        """
        if mod == B('#') and char == B('8'):
            self.decaln()
        elif mod == B('%'): # select main character set
            if char == B('@'):
                self.modes.main_charset = CHARSET_DEFAULT
            elif char in B('G8'):
                # 8 is obsolete and only for backwards compatibility
                self.modes.main_charset = CHARSET_UTF8
        elif mod == B('(') or mod == B(')'): # define G0/G1
            self.set_g01(char, mod)
        elif char == B('M'): # reverse line feed
            self.linefeed(reverse=True)
        elif char == B('D'): # line feed
            self.linefeed()
        elif char == B('c'): # reset terminal
            self.reset()
        elif char == B('E'): # newline