@Override
  public MeasurementPath fetchMeasurementPath(final PartialPath fullPath) throws MetadataException {
    final IMeasurementMNode<IMemMNode> node = mTree.getMeasurementMNode(fullPath);
    final MeasurementPath res = new MeasurementPath(node.getPartialPath(), node.getSchema());
    res.setUnderAlignedEntity(node.getParent().getAsDeviceMNode().isAligned());
    return res;
  }
get device node, if the schema region is not set, create it when autoCreateSchema is true

<p>(we develop this method as we need to get the node's lock after we get the lock.writeLock())

@param path path
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/impl/SchemaRegionMemoryImpl.java