text: import pytest
  from qmap_interpolation import Instrument, Size, angstrom, mm, BeamCenter
  
  
  @pytest.fixture()
  def instrument():
      beam_center = BeamCenter(0, 0)
      size = Size(100, 200)
      wavelength = 10 * angstrom
      pixel_size = 7 * mm
      return Instrument(wavelength, size, pixel_size)
  