'Show hover labels over the points specified in hover_obj.
Hover labels are the labels that normally appear when the
mouse hovers over points in the plotly graph.
Args:
hover_objs (tuple of dicts):
Specifies which points to place hover labels over.
The location of the hover labels is described by a dict with
keys and\'xval\' and/or \'yval\' or \'curveNumber\' and \'pointNumber\'
and optional keys \'hovermode\' and \'subplot\'
\'xval\' and \'yval\' specify the (x, y) coordinates to
place the label.
\'xval\' and \'yval need to be close to a point drawn in a graph.
\'curveNumber\' and \'pointNumber\' specify the trace number and
the index theof the point in that trace respectively.
\'subplot\' describes which axes to the coordinates refer to.
By default, it is equal to \'xy\'. For example, to specify the
second x-axis and the third y-axis, set \'subplot\' to \'x2y3\'
\'hovermode\' is either \'closest\', \'x\', or \'y\'.
When set to \'x\', all data sharing the same \'x\' coordinate will
be shown on screen with corresponding trace labels.
When set to \'y\' all data sharing the same \'y\' coordinates will
be shown on the screen with corresponding trace labels.
When set to \'closest\', information about the data point closest
to where the viewer is hovering will appear.
Note: If \'hovermode\' is \'x\', only \'xval\' needs to be set.
If \'hovermode\' is \'y\', only \'yval\' needs to be set.
If \'hovermode\' is \'closest\', \'xval\' and \'yval\' both
need to be set.
Note: \'hovermode\' can be toggled by the user in the graph
toolbar.
Note: It is not currently possible to apply multiple hover
labels to points on different axes.
Note: `hover` can only be called with multiple dicts if
\'curveNumber\' and \'pointNumber\' are the keys of the dicts
Examples:
Initialization - Start each example below with this setup:
from plotly.widgets import GraphWidget
from IPython.display import display
graph = GraphWidget(\'https://plot.ly/~chris/3979\')
display(graph)
Example 1 - Apply a label to the (x, y) point (3, 2)
graph.hover({\'xval\': 3, \'yval\': 2, \'hovermode\': \'closest\'})
Example 2 -Apply a labels to all the points with the x coordinate 3
graph.hover({\'xval\': 3, \'hovermode\': \'x\'})
Example 3 - Apply a label to the first point of the first trace
and the second point of the second trace.
graph.hover({\'curveNumber\': 0, \'pointNumber\': 0},
{\'curveNumber\': 1, \'pointNumber\': 1})'

def hover(self, *hover_objs):

    if (len(hover_objs) == 1):
        hover_objs = hover_objs[0]
    message = {'task': 'hover', 'selection': hover_objs, 'graphId': self._graphId}
    self._handle_outgoing_message(message)
