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node_modules/one-time/index.js

@@ -0,0 +1,37 @@
+'use strict';
+
+/**
+ * Wrap callbacks to prevent double execution.
+ *
+ * @param {Function} fn Function that should only be called once.
+ * @returns {Function} A wrapped callback which prevents execution.
+ * @api public
+ */
+module.exports = function one(fn) {
+  var called = 0
+    , value;
+
+  /**
+   * The function that prevents double execution.
+   *
+   * @api private
+   */
+  function onetime() {
+    if (called) return value;
+
+    called = 1;
+    value = fn.apply(this, arguments);
+    fn = null;
+
+    return value;
+  }
+
+  //
+  // To make debugging more easy we want to use the name of the supplied
+  // function. So when you look at the functions that are assigned to event
+  // listeners you don't see a load of `onetime` functions but actually the
+  // names of the functions that this module will call.
+  //
+  onetime.displayName = fn.displayName || fn.name || onetime.displayName || onetime.name;
+  return onetime;
+};