code: def get_entries_in_chemsys(self, elements, compatible_only=True,
                                 inc_structure=None, property_data=None,
                                 conventional_unit_cell=False):
          
          entries = []
          for i in range(len(elements)):
              for els in itertools.combinations(elements, i + 1):
                  entries.extend(
                      self.get_entries(
                          "-".join(els), compatible_only=compatible_only,
                          inc_structure=inc_structure,
                          property_data=property_data,
                          conventional_unit_cell=conventional_unit_cell))
          return entries
docs: Helper method to get a list of ComputedEntries in a chemical system.
          For example, elements = ["Li", "Fe", "O"] will return a list of all
          entries in the Li-Fe-O chemical system, i.e., all LixOy,
          FexOy, LixFey, LixFeyOz, Li, Fe and O phases. Extremely useful for
          creating phase diagrams of entire chemical systems.
  
          Args:
              elements ([str]): List of element symbols, e.g., ["Li", "Fe",
                  "O"].
              compatible_only (bool): Whether to return only "compatible"
                  entries. Compatible entries are entries that have been
                  processed using the MaterialsProjectCompatibility class,
                  which performs adjustments to allow mixing of GGA and GGA+U
                  calculations for more accurate phase diagrams and reaction
                  energies.
              inc_structure (str): If None, entries returned are
                  ComputedEntries. If inc_structure="final",
                  ComputedStructureEntries with final structures are returned.
                  Otherwise, ComputedStructureEntries with initial structures
                  are returned.
              property_data (list): Specify additional properties to include in
                  entry.data. If None, no data. Should be a subset of
                  supported_properties.
              conventional_unit_cell (bool): Whether to get the standard
                  conventional unit cell
  
          Returns:
              List of ComputedEntries.