message: impl is-transmembrane symbol correctly
diff: */
  import { ParamDefinition as PD } from '../../mol-util/param-definition';
  -import { Structure, StructureProperties } from '../../mol-model/structure';
  +import { Structure, StructureProperties, Unit } from '../../mol-model/structure';
  import { CustomPropertyDescriptor } from '../../mol-model/custom-property';
  import { ANVILParams, ANVILProps, computeANVIL, isInMembranePlane } from './ANVIL';
  import { CustomStructureProperty } from '../../mol-model-props/common/custom-structure-property';
  @@ -41,11 +41,11 @@ const pos = Vec3();
  export const MembraneOrientationSymbols = {
  isTransmembrane: QuerySymbolRuntime.Dynamic(CustomPropSymbol('computed', 'membrane-orientation.is-transmembrane', Type.Bool),
  ctx => {
  - const structure = ctx.currentStructure;
  + const { unit, structure } = ctx.element;
  const { x, y, z } = StructureProperties.atom;
  - if (!structure.isAtomic) return false;
  + if (!Unit.isAtomic(unit)) return 0;
  const membraneOrientation = MembraneOrientationProvider.get(structure).value;
  - if (!membraneOrientation) return false;
  + if (!membraneOrientation) return 0;
  Vec3.set(pos, x(ctx.element), y(ctx.element), z(ctx.element));
  const { normalVector, planePoint1, planePoint2 } = membraneOrientation!;
  return isInMembranePlane(pos, normalVector, planePoint1, planePoint2);
  