function connectionTest_setUp() {
  dummyWorkspace = {};
  input = new Blockly.Connection({workspace: dummyWorkspace},
      Blockly.INPUT_VALUE);
  output = new Blockly.Connection({workspace: dummyWorkspace},
      Blockly.OUTPUT_VALUE);
  previous = new Blockly.Connection({workspace: dummyWorkspace},
      Blockly.PREVIOUS_STATEMENT);
  next = new Blockly.Connection({workspace: dummyWorkspace},
      Blockly.NEXT_STATEMENT);
}
@fileoverview Tests for connection logic.
@author fenichel@google.com (Rachel Fenichel)