import axiom without dependency on symfony console

axiom_src/Atoms/StringAtom.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Enzyme\Axiom\Atoms;
+
+use Enzyme\Axiom\Exceptions\AtomException;
+
+class StringAtom implements AtomInterface
+{
+    protected $value;
+
+    public function __construct($value)
+    {
+        if (is_string($value) === false) {
+            throw new AtomException(get_class($this), $value);
+        }
+
+        $this->value = $value;
+    }
+
+    public function getValue()
+    {
+        return $this->value;
+    }
+}