PyQt5 QTextEdit limiting buffer

Is it possible to use PyQt5 to limit the number of lines in QTextEdit? I read about setMaximumBlockCount but can't seem to figure out how to actually use it on QTextEdit. Would anyone have an example they could give me? Here's a sample code I would like to use to do something like that...

Code:

import sys
from PyQt5.QtWidgets import (QMainWindow, QTextEdit, QApplication, QLineEdit,
                             QVBoxLayout, QFrame)
 
class Example(QMainWindow):
    def __init__(self):
        super().__init__()
        self.ex_frame = QFrame(self)
        self.ex_frame.setObjectName("ex_frame")
 
        self.ex_out = QTextEdit(self.ex_frame)
        self.ex_out.setReadOnly(True)
        self.ex_out.setObjectName("ex_out")
        self.ex_in = QLineEdit(self.ex_frame)
        self.ex_in.setFocus(True)
        self.ex_in.setObjectName("ex_in")
        self.ex_in.returnPressed.connect(self.execute_command)
        vbox = QVBoxLayout(self.ex_frame)
        vbox.addWidget(self.ex_out)
        vbox.addWidget(self.ex_in)
        self.setCentralWidget(self.ex_frame)
 
        self.setGeometry(300, 300, 720, 480)
        self.setWindowTitle('Example')
        self.show()
 
    def execute_command(self):
        self.ex_out.append(self.ex_in.text())
        self.ex_in.setText('')
 
if __name__ == '__main__':
    app = QApplication(sys.argv)
    Ex = Example()
    sys.exit(app.exec_())

Any help would be appreciated. Thanks.