content: import React from 'react';
  import PropTypes from 'prop-types';
  import Grid from 'material-ui/Grid';
  import { withStyles } from 'material-ui/styles';
  
  /** Custom grid column based on flexbox
   * - used instead of materia-ui one to avoid strange spacing
   * issues when multiple grid columns being nested in each other
   * currently supports only one spacing - 12px
   * */
  
  const styleSheet = theme => ({
    grid: {
      display: 'flex',
      flexDirection: 'column',
      margin: -(theme.spacing.unit * 1.5),
    },
    gridItem: {
      padding: theme.spacing.unit * 1.5,
    },
  });
  
  function CustomGridColumn(props) {
    const { classes, children, spacing, ...other } = props;
    return (
      <div className={classes.grid} >
        {React.Children.map(children, child =>
          (child
            ? <div className={classes.gridItem} >
              {child}
            </div>
            : null))}
      </div>
    );
  }
  
  CustomGridColumn.propTypes = {
    classes: PropTypes.object,
    children: PropTypes.node,
  };
  
  
  export default withStyles(styleSheet, { name: 'CustomGridColumn' })(CustomGridColumn);
  