<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def handle_read(self):
 """We got some output from a remote shell, this is one of the state machine"""

        if self.state == STATE_DEAD:
            return
        global nr_handle_read
        nr_handle_read += 1
        new_data = self._handle_read_chunk()
        if self.debug:
            self.print_debug(b'==> ' + new_data)
        if self.handle_read_fast_case(self.read_buffer):
            return
        lf_pos = new_data.find(b'\n')
        if lf_pos >= 0:
            # Optimization: we knew there were no '\n' in the previous read
            # buffer, so we searched only in the new_data and we offset the
            # found index by the length of the previous buffer
            lf_pos += len(self.read_buffer) - len(new_data)
        elif self.state is STATE_NOT_STARTED and \
                options.password is not None and \
                b'password:' in self.read_buffer.lower():
            self.dispatch_write('{}\n'.format(options.password).encode())
            self.read_buffer = b''
            return
        while lf_pos >= 0:
            # For each line in the buffer
            line = self.read_buffer[:lf_pos + 1]
            if callbacks.process(line):
                pass
            elif self.state in (STATE_IDLE, STATE_RUNNING):
                self.print_lines(line)
            elif self.state is STATE_NOT_STARTED:
                self.read_in_state_not_started += line
                if b'The authenticity of host' in line:
                    msg = line.strip(b'\n') + b' Closing connection.'
                    self.disconnect()
                elif b'REMOTE HOST IDENTIFICATION HAS CHANGED' in line:
                    msg = b'Remote host identification has changed.'
                else:
                    msg = None

                if msg:
                    self.print_lines(msg + b' Consider manually connecting or '
                                     b'using ssh-keyscan.')

            # Go to the next line in the buffer
            self.read_buffer = self.read_buffer[lf_pos + 1:]
            if self.handle_read_fast_case(self.read_buffer):
                return
            lf_pos = self.read_buffer.find(b'\n')
        if self.state is STATE_NOT_STARTED and not self.init_string_sent:
            self.dispatch_write(self.init_string)
            self.init_string_sent = True