PythonQt: missing slot

[dbrnz]

When clicking button to edit axis in matplotlib. This is when showing a figure with two subplots.

  File "/Users/dave/build/OpenCOR-upstream/build/OpenCOR.app/Contents/Frameworks/Python/lib/python3.5/site-packages/matplotlib/backends/backend_qt5.py", line 677, in edit_parameters
    self.parent, 'Customize', 'Select axes:', titles, 0, False)
ValueError: Could not find matching overload for given arguments:
(<qt slot parent of NavigationToolbar2QT instance at 0x127af9b88>, 'Customize', 'Select axes:', ['Time (ms) - Na_i (millimolar)', 'Time (ms) - Membrane voltage (mV)'], 0, False)
 The following slots are available:
static getItem(QWidget parent, QString title, QString label, QStringList items, int current, bool editable, PythonQt.BoolResult ok, Qt::WindowFlags flags, Qt::InputMethodHints inputMethodHints) -> QString
static getItem(QWidget parent, QString title, QString label, QStringList items, int current, bool editable, PythonQt.BoolResult ok, Qt::WindowFlags flags) -> QString
static getItem(QWidget parent, QString title, QString label, QStringList items, int current, bool editable, PythonQt.BoolResult ok) -> QString
static getItem(QWidget parent, QString title, QString label, QStringList items, int current, bool editable) -> QString
static getItem(QWidget parent, QString title, QString label, QStringList items, int current) -> QString
static getItem(QWidget parent, QString title, QString label, QStringList items) -> QString