attaching schema nodes progress

source/core/utils/primary_key_attribute.cpp

@@ -0,0 +1,15 @@
+#include "matador/utils/primary_key_attribute.hpp"
+
+namespace matador::utils {
+primary_key_attribute::primary_key_attribute(const size_t size)
+: size_(size) {}
+
+primary_key_attribute& primary_key_attribute::operator=(const size_t size) {
+    size_ = size;
+    return *this;
+}
+
+size_t primary_key_attribute::size() const {
+    return size_;
+}
+}