code: def from_sites(cls, sites, charge=None, validate_proximity=False,
                     to_unit_cell=False):
          
          if len(sites) < 1:
              raise ValueError("You need at least one site to construct a %s" %
                               cls)
          prop_keys = []
          props = {}
          lattice = None
          for i, site in enumerate(sites):
              if not lattice:
                  lattice = site.lattice
              elif site.lattice != lattice:
                  raise ValueError("Sites must belong to the same lattice")
              for k, v in site.properties.items():
                  if k not in prop_keys:
                      prop_keys.append(k)
                      props[k] = [None] * len(sites)
                  props[k][i] = v
          for k, v in props.items():
              if any((vv is None for vv in v)):
                  warnings.warn("Not all sites have property %s. Missing values "
                                "are set to None." % k)
          return cls(lattice, [site.species for site in sites],
                     [site.frac_coords for site in sites],
                     charge=charge,
                     site_properties=props,
                     validate_proximity=validate_proximity,
                     to_unit_cell=to_unit_cell)
docs: Convenience constructor to make a Structure from a list of sites.
  
          Args:
              sites: Sequence of PeriodicSites. Sites must have the same
                  lattice.
              validate_proximity (bool): Whether to check if there are sites
                  that are less than 0.01 Ang apart. Defaults to False.
              to_unit_cell (bool): Whether to translate sites into the unit
                  cell.
  
          Returns:
              (Structure) Note that missing properties are set as None.