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diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/model/Attribute.java b/src/main/java/pl/edu/mimuw/cloudatlas/model/Attribute.java
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+/**
+ * Copyright (c) 2014, University of Warsaw
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted
+ * provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of
+ * conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+ * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package pl.edu.mimuw.cloudatlas.model;
+
+/**
+ * Represents an attribute (without value, name only).
+ * <p>
+ * A valid attribute name is an identifier starting with a letter and containing only letters and digits. It can
+ * additionally start with an ampersand - such names are reserved for queries.
+ * <p>
+ * This class is immutable.
+ */
+public class Attribute {
+    private final String name;
+
+    /**
+     * Creates a new <code>Attribute</code> object with the specified <code>name</code>.
+     *
+     * @param name the name of the attribute
+     * @throws IllegalArgumentException if the <code>name</code> does not meet the rules
+     */
+    public Attribute(String name) {
+        if(!name.matches("^&?[a-zA-Z]{1}[a-zA-z0-9_]*$"))
+            throw new IllegalArgumentException("Invalid name: may contain only letters, digits, underscores, "
+                    + "must start with a letter and may optionally have an ampersand at the beginning.");
+        this.name = name;
+    }
+
+    /**
+     * Indicates whether an <code>attribute</code> represents a query. This is true if and only if the attribute's name starts with an ampersand.
+     *
+     * @param attribute the attribute to check
+     * @return whether the <code>attribute</code> represents a query
+     */
+    public static boolean isQuery(Attribute attribute) {
+        return attribute.getName().startsWith("&");
+    }
+
+    /**
+     * Gets the name of this attribute.
+     *
+     * @return string representing name
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Returns a hash code value for this attribute. For proper behavior when using <code>Attribute</code> objects in
+     * <code>HashMap</code>, <code>HashSet</code> etc. this is the hash code of a string representing the attribute's name.
+     *
+     * @return hash code for this attribute
+     */
+    @Override
+    public int hashCode() {
+        return name.hashCode();
+    }
+
+    /**
+     * Indicates whether another object is equal to this attribute.
+     *
+     * @param object the object to check
+     * @return true if and only if the <code>object</code> is an instance of <code>Attribute</code> class and has
+     * an identical name
+     */
+    @Override
+    public boolean equals(Object object) {
+        if(object == null)
+            return false;
+        if(getClass() != object.getClass())
+            return false;
+        return name.equals(((Attribute)object).name);
+    }
+
+    /**
+     * Returns a textual representation of this attribute.
+     *
+     * @return the name of this attribute
+     */
+    @Override
+    public String toString() {
+        return name;
+    }
+}