old_contents: import plotly
  from plotly.graph_objs import *
  import plotly.tools as tls
  from nose.tools import raises
  import numpy as np
  
  
  @raises(Exception)
  def unequal_xy_length():
      data = tls.Quiver(x=[1, 2], y=[1], u=[1, 2], v=[1, 2])
  
  
  @raises(Exception)
  def unequal_uv_length():
      data = tls.Quiver(x=[1, 2], y=[1, 3], u=[1], v=[1, 2])
  
  
  @raises(Exception)
  def test_wrong_kwarg():
      data = tls.Quiver(stuff='not gonna work')
  
  
  def test_one_arrow():
      nan = np.nan
      trace1 = Scatter(
              x=np.array([0., 1., nan]),
              y=np.array([0., 1., nan]),
              mode='lines',
              name='Barb',
              line=Line(color='rgb(114, 132, 314)', width=1)
              )
      trace2 = Scatter(
              x=np.array([0.82069826, 1., 0.61548617, nan]),
              y=np.array([0.61548617,  1.,  0.82069826, nan]),
              mode='lines',
              name='Arrow',
              line=Line(color='rgb(114, 132, 314)', width=1)
              )
      expected = Data([trace1, trace2])
      assert tls.Quiver(x=[0], y=[0], u=[1], v=[1], scale=1) == expected
  
new_contents: import plotly
  from plotly.graph_objs import *
  import plotly.tools as tls
  from nose.tools import raises
  import numpy as np
  
  
  @raises(Exception)
  def unequal_xy_length():
      data = tls.Quiver(x=[1, 2], y=[1], u=[1, 2], v=[1, 2])
  
  
  @raises(Exception)
  def unequal_uv_length():
      data = tls.Quiver(x=[1, 2], y=[1, 3], u=[1], v=[1, 2])
  
  
  @raises(Exception)
  def test_wrong_kwarg():
      data = tls.Quiver(stuff='not gonna work')
  
  
  def test_one_arrow():
      nan = np.nan
      trace1 = Scatter(
              x=[0., 1., nan],
              y=[0., 1., nan],
              mode='lines',
              name='Barb',
              line=Line(color='rgb(114, 132, 314)', width=1)
              )
      trace2 = Scatter(
              x=np.array([0.82069826, 1., 0.61548617, nan]),
              y=np.array([0.61548617,  1.,  0.82069826, nan]),
              mode='lines',
              name='Arrow',
              line=Line(color='rgb(114, 132, 314)', width=1)
              )
      expected = Data([trace1, trace2])
      assert tls.Quiver(x=[0], y=[0], u=[1], v=[1], scale=1) == expected
  
subject: change from arrays to lists