How was the Spanish Civil War significant to the Nazi army prior to World War II?

The Spanish Civil War (1936-9) was a very important event during the tense1930s in Europe. Although it did not make World War II inevitable, it increased the likelihood of a general war a great deal. The war had a tremendous impact on Spain itself, leaving much of the state's economic and social infrastructure in ruins and leaving thousands dead. But the war also saw involvement from other European states as both sides of the conflict - the Right-wing Nationalists and the Left-wing Republicans (a. k. a. Loyalists) - requested and received foreign aid not only in terms of financial assets, but also in terms of war material and troops. Adolf Hitler's Germany was one of the foreign countries most involved in the conflict, contributing economic loans as well as several thousand troops to the Nationalist cause. Hitler's involvement in the Spanish war was consistent with a larger Nazi foreign policy aimed at diverting British and French attention from Central and Eastern Europe so that he would be unhindered in his plans for eastern expansion.