How to use the @uifabric/styling.ColorClassNames.neutralSecondary function in @uifabric/styling

tooltipProps={{
                        onRenderContent: () => (
                          <div>
                            {HISTORY_API_ERROR_MESSAGE}
                          </div>
                        ),
                      }}
                      directionalHint={DirectionalHint.topLeftEdge}
                    &gt;
                      <div>
                        
                      </div>
                    
                  
                )}
              
            
            <div>
              <span>
                </span></div>

FontClassNames.medium,
                ColorClassNames.neutralSecondary,
              )}
              style={{ marginBottom: spacing.s1 }}
            >
              Duration:
            
            <div>
              {getAttemptDurationString(jobRetry)}
            </div>
          
          <div>
            <div style="{{">
              Exit Code:
            </div>
            <div>
              {`${jobRetry.exitCode}`}
            </div>
          </div>
          <div>
            </div>

<div style="{{">
            <span style="{{">Retry Index:</span>
            <span>{jobRetry.attemptIndex}</span>
          </div>
        
        
          <div>
            <div style="{{">
              Status:
            </div>
            
          </div>
          <div>
            <div style="{{">
              Start Time:</div></div>

>{`#${x}`}
                        ))}
                      
                    ),
                  }}
                  directionalHint={DirectionalHint.topLeftEdge}
                >
                  
                    <div>{gpuAttr.length}</div>
                    <div>
                      
                    </div>
                  
                
              
            );
          }
        },
      },