Reading a sample of particle data - list-indexing

It appears to not be possible to select a "sample" of particles from a file except by reading all particles (en-block or in chunks) and selecting thereafter.

I'd like to be able to read the particle data (here: positions) only for a list of particle indices:

An attempt along the lines of :
```python

timestep=106000
species="e"
particleIndices = [1024, 123, 42]

iteration = series.iterations[timestep]
xpos_incell = iteration.particles[species]["position"]["x"][particleIndices]
```

fails with the following:
```
TypeError: __getitem__(): incompatible function arguments. The following argument types are supported:
1. (self: openpmd_api.openpmd_api_cxx.Record_Component, tuple of index slices: tuple) -> numpy.ndarray
2. (self: openpmd_api.openpmd_api_cxx.Record_Component, slice: slice) -> numpy.ndarray
3. (self: openpmd_api.openpmd_api_cxx.Record_Component, axis index: int) -> numpy.ndarray

[...]
```

If such an access is not envisioned this should be noted explicitly (e.g. in the documentation). If there is a way of achieving the above I'd welcome the help.

**Software Environment:**
Using openPMD 0.14.4 installed from source and reading from an ADIOS2 file.