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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 2.1 - 2.2 Migration
Step1:  In the default mode, you can change which of the stars you'd like to provide the luminosity.  By default, this is the primary component.  To provide the luminosity of the secondary star instead, set pblum_component.  
Previously this was achieved by setting pblum_ref@primary = 'secondary' and pblum_ref@secondary = 'self'.  Note that the pblum_ref parameter has been removed in 2.2+ in favor of the more flexible and intuitive pblum_mode parameter.
Step2:  Previously, you could 'decouple' the luminisoties by setting pblum_ref of both components to 'self'.  In PHOEBE 2.2+, you will instead change pblum_mode to 'decoupled', in which case multiple pblum parameters will become visible.
Step3:  For more information on the behavior for all of these supported modes, see the pblum tutorial.
In addition, PHOEBE 2.2 distinguishes between intrinsic passband luminosities (pblum) and extrinsic passband luminosities (pblum_ext).  The returned dictionary from b.compute_pblums now includes both intrinsic and extrinsic values, with the keys of the dictionary now including pblum@ or pblum_ext@.
Step4:  This also means that the mesh column to expose luminosities is renamed to pblum_ext (and abs_pblum_ext) as these expose the extrinsic luminosities (including features such as spots, irradiation, etc).
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Python Code:
import phoebe
b = phoebe.default_binary()
b.add_dataset('lc', dataset='lc01')
print(b.filter(qualifier='pblum*', dataset='lc01'))
print(b.get_parameter('pblum_mode'))
Explanation: 2.1 - 2.2 Migration: pblum_mode and pblum vs pblum_ext
PHOEBE 2.2 introduces new modes for handling the scaling between absolute and relative luminosities/intensities/fluxes via the new pblum_mode parameter, which will exist for each LC dataset attached to the bundle.  By default pblum_mode will be set to 'component-coupled', which mimics the default behavior prior to version 2.2.
End of explanation
print(b.get_parameter('pblum_component'))
b.set_value('pblum_component', 'secondary')
print(b.filter(qualifier='pblum*', dataset='lc01'))
Explanation: In the default mode, you can change which of the stars you'd like to provide the luminosity.  By default, this is the primary component.  To provide the luminosity of the secondary star instead, set pblum_component.  
Previously this was achieved by setting pblum_ref@primary = 'secondary' and pblum_ref@secondary = 'self'.  Note that the pblum_ref parameter has been removed in 2.2+ in favor of the more flexible and intuitive pblum_mode parameter.
End of explanation
b.set_value('pblum_mode', 'decoupled')
print(b.filter(qualifier='pblum*', dataset='lc01'))
Explanation: Previously, you could 'decouple' the luminisoties by setting pblum_ref of both components to 'self'.  In PHOEBE 2.2+, you will instead change pblum_mode to 'decoupled', in which case multiple pblum parameters will become visible.
End of explanation
print(b.compute_pblums())
Explanation: For more information on the behavior for all of these supported modes, see the pblum tutorial.
In addition, PHOEBE 2.2 distinguishes between intrinsic passband luminosities (pblum) and extrinsic passband luminosities (pblum_ext).  The returned dictionary from b.compute_pblums now includes both intrinsic and extrinsic values, with the keys of the dictionary now including pblum@ or pblum_ext@.
End of explanation
b.add_dataset('mesh', dataset='mesh01')
print(b.get_parameter('columns', dataset='mesh01').choices)
Explanation: This also means that the mesh column to expose luminosities is renamed to pblum_ext (and abs_pblum_ext) as these expose the extrinsic luminosities (including features such as spots, irradiation, etc).
End of explanation
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