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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def getStretchTwistBendModulus(self, bp, frames=None, paxis='Z', masked=True, matrix=False):
 r"""Calculate Bending-Stretching-Twisting matrix It calculate elastic matrix and modulus matrix. .. math:: \text{modulus matrix} = 4.1419464 \times \begin{bmatrix} K_{Bx} & K_{Bx,By} & K_{Bx,S} & K_{Bx,T} \\ K_{Bx,By} & K_{By} & K_{By,S} & K_{By,T} \\ K_{Bx,S} & K_{By,S} & K_{S} & K_{S,T} \\ K_{Bx,T} & K_{Bx,T} & K_{S,T} & K_{T} \end{bmatrix} \times L_0 .. currentmodule:: dnaMD Parameters bp : list List of two base-steps forming the DNA segment. For example: with ``bp=[5, 50]``, 5-50 base-step segment will be considered. frames : list List of two trajectory frames between which parameters will be extracted. It can be used to select portions of the trajectory. For example, with ``frames=[100, 1000]``, 100th to 1000th frame of the trajectory will be considered. paxis : str Axis parallel to global helical-axis(``'X'``, or ``'Y'`` or ``'Z'``). Only require when bending motions are included in the calculation. masked : bool ``Default=False``. To skip specific frames/snapshots. ``DNA.mask`` array should be set to use this functionality. This array contains boolean (either ``True`` or ``False``) value for each frame to mask the frames. Presently, mask array is automatically generated during :meth:`dnaMD.DNA.generate_smooth_axis` to skip those frames where 3D fitting curve was not successful within the given criteria. matrix : bool If it is ``True``, elastic constant matrix will be returned. Otherwise, by default modulus matrix will be returned. Return ------ mean : numpy.ndarray Value of bending angles, contour length and twist angle (as 1D array) at which energy is zero. Minimum point on free energy landscape. .. math:: \begin{bmatrix} \theta^{x}_0 & \theta^{y}_0 & L_0 & \phi_0 \end{bmatrix} result : numpy.ndarray Either elastic matrix or modulus matrix depending on ``matrix`` value. """



        if self.esType == 'ST':
            raise KeyError(' Use dnaEY.getStretchTwistModulus for Stretching-Twisting modulus.')

        frames = self._validateFrames(frames)

        name = '{0}-{1}-{2}-{3}'.format(bp[0], bp[1], frames[0], frames[1])

        if name not in self.esMatrix:
            time, array = self.extractGlobalParameters(self.dna, bp, frames=frames, paxis=paxis, masked=masked)
            mean = np.mean(array, axis=1)
            esMatrix = np.asarray(self.getElasticMatrix(array))
            self.esMatrix[name] = esMatrix
            self.minimumPoint[name] = mean
        else:
            esMatrix = self.esMatrix[name]
            mean = self.minimumPoint[name]

        if not matrix:
            result = 4.1419464 * np.array(esMatrix) * mean[2]       # Calculate modulus
        else:
            result = esMatrix

        return mean, result