How to use the @patternfly/react-charts.getCustomTheme function in @patternfly/react-charts

import { Dropdown, humanizeNumberSI, LoadingInline, usePoll, useRefWidth, useSafeFetch } from '../utils';
import {
  formatPrometheusDuration,
  parsePrometheusDuration,
  twentyFourHourTime,
  twentyFourHourTimeWithSeconds,
} from '../utils/datetime';
import { withFallback } from '../utils/error-boundary';
import { PrometheusResponse } from '../graphs';
import { GraphEmpty } from '../graphs/graph-empty';
import { getPrometheusURL, PrometheusEndpoint } from '../graphs/helpers';
import { queryBrowserTheme } from '../graphs/themes';

const spans = ['5m', '15m', '30m', '1h', '2h', '6h', '12h', '1d', '2d', '1w', '2w'];
const dropdownItems = _.zipObject(spans, spans);
const chartTheme = getCustomTheme(ChartThemeColor.multi, ChartThemeVariant.light, queryBrowserTheme);
export const colors = chartTheme.line.colorScale;

// Use exponential notation for small or very large numbers to avoid labels with too many characters
const formatPositiveValue = (v: number): string => v === 0 || (0.001 <= v && v < 1e23)
  ? humanizeNumberSI(v).string
  : v.toExponential(1);
const formatValue = (v: number): string => (v < 0 ? '-' : '') + formatPositiveValue(Math.abs(v));

export const Error = ({error, title = 'An error occurred'}) =>
  
    {_.get(error, 'json.error', error.message)}
  ;

const GraphEmptyState = ({children, title}) =&gt; <div>
  
    </div>