new position factory methods

Author: Kajetan Fuchsberger

src/java/org/tensorics/core/tensor/Positions.java

@@ -33,6 +33,8 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
+import org.mockito.internal.util.collections.Iterables;
+
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
@@ -384,6 +386,15 @@ public static Set<Position> cartesianProduct(Iterable<Set<?>> coordinateSets) {
         return cartesianProduct.stream().map(l -> Position.of(new HashSet<>(l))).collect(toSet());
     }
 
+    public static <T> Set<Position> from(Collection<T> coordinates) {
+        return coordinates.stream().map(t -> Position.of(t)).collect(toSet());
+    }
+    
+    public static <T> Set<Position> from(T ... coordinates) {
+        return from(ImmutableSet.copyOf(coordinates));
+    }
+    
+    
     /**
      * Returns a position which contains the coordinates which are contained in the left position but not in the right
      * position. The right position might also contain coordinates not contained in the left position, which are simply